diff --git a/.eslintrc.js b/.eslintrc.js
index 3a755c032e..0dc85ad9a9 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -107,6 +107,36 @@ module.exports = {
         property,
         message: `Use ${alternative} instead.`,
       })),
+      ...[
+        'readdirSync',
+        'readFileSync',
+        'statSync',
+        'lstatSync',
+        'existsSync',
+        'pathExistsSync',
+        'realpathSync',
+        'mkdirSync',
+        'mkdirpSync',
+        'mkdirsSync',
+        'writeFileSync',
+        'writeJsonSync',
+        'outputFileSync',
+        'outputJsonSync',
+        'moveSync',
+        'copySync',
+        'copyFileSync',
+        'ensureFileSync',
+        'ensureDirSync',
+        'ensureLinkSync',
+        'ensureSymlinkSync',
+        'unlinkSync',
+        'removeSync',
+        'emptyDirSync',
+      ].map((property) => ({
+        object: 'fs',
+        property,
+        message: 'Do not use sync fs methods.',
+      })),
     ],
     'no-restricted-syntax': [
       WARNING,
diff --git a/packages/create-docusaurus/src/index.ts b/packages/create-docusaurus/src/index.ts
index 9d8024fc89..6a7398a2a6 100755
--- a/packages/create-docusaurus/src/index.ts
+++ b/packages/create-docusaurus/src/index.ts
@@ -37,16 +37,14 @@ async function updatePkg(pkgPath: string, obj: Record<string, unknown>) {
   await fs.outputFile(pkgPath, `${JSON.stringify(newPkg, null, 2)}\n`);
 }
 
-function readTemplates(templatesDir: string) {
-  const templates = fs
-    .readdirSync(templatesDir)
-    .filter(
-      (d) =>
-        !d.startsWith('.') &&
-        !d.startsWith('README') &&
-        !d.endsWith(TypeScriptTemplateSuffix) &&
-        d !== 'shared',
-    );
+async function readTemplates(templatesDir: string) {
+  const templates = (await fs.readdir(templatesDir)).filter(
+    (d) =>
+      !d.startsWith('.') &&
+      !d.startsWith('README') &&
+      !d.endsWith(TypeScriptTemplateSuffix) &&
+      d !== 'shared',
+  );
 
   // Classic should be first in list!
   return _.sortBy(templates, (t) => t !== RecommendedTemplate);
@@ -86,8 +84,8 @@ async function copyTemplate(
   if (tsBaseTemplate) {
     const tsBaseTemplatePath = path.resolve(templatesDir, tsBaseTemplate);
     await fs.copy(tsBaseTemplatePath, dest, {
-      filter: (filePath) =>
-        fs.statSync(filePath).isDirectory() ||
+      filter: async (filePath) =>
+        (await fs.stat(filePath)).isDirectory() ||
         path.extname(filePath) === '.css' ||
         path.basename(filePath) === 'docusaurus.config.js',
     });
@@ -96,7 +94,7 @@ async function copyTemplate(
   await fs.copy(path.resolve(templatesDir, template), dest, {
     // Symlinks don't exist in published NPM packages anymore, so this is only
     // to prevent errors during local testing
-    filter: (filePath) => !fs.lstatSync(filePath).isSymbolicLink(),
+    filter: async (filePath) => !(await fs.lstat(filePath)).isSymbolicLink(),
   });
 }
 
@@ -135,9 +133,9 @@ export default async function init(
 ): Promise<void> {
   const useYarn = cliOptions.useNpm ? false : hasYarn();
   const templatesDir = fileURLToPath(new URL('../templates', import.meta.url));
-  const templates = readTemplates(templatesDir);
+  const templates = await readTemplates(templatesDir);
   const hasTS = (templateName: string) =>
-    fs.pathExistsSync(
+    fs.pathExists(
       path.resolve(templatesDir, `${templateName}${TypeScriptTemplateSuffix}`),
     );
 
@@ -160,7 +158,7 @@ export default async function init(
   }
 
   const dest = path.resolve(rootDir, name);
-  if (fs.existsSync(dest)) {
+  if (await fs.pathExists(dest)) {
     logger.error`Directory already exists at path=${dest}!`;
     process.exit(1);
   }
@@ -176,7 +174,7 @@ export default async function init(
       choices: createTemplateChoices(templates),
     });
     template = templatePrompt.template;
-    if (template && !useTS && hasTS(template)) {
+    if (template && !useTS && (await hasTS(template))) {
       const tsPrompt = await prompts({
         type: 'confirm',
         name: 'useTS',
@@ -223,10 +221,10 @@ export default async function init(
     const dirPrompt = await prompts({
       type: 'text',
       name: 'templateDir',
-      validate: (dir?: string) => {
+      validate: async (dir?: string) => {
         if (dir) {
           const fullDir = path.resolve(process.cwd(), dir);
-          if (fs.existsSync(fullDir)) {
+          if (await fs.pathExists(fullDir)) {
             return true;
           }
           return logger.red(
@@ -267,7 +265,7 @@ export default async function init(
   } else if (templates.includes(template)) {
     // Docusaurus templates.
     if (useTS) {
-      if (!hasTS(template)) {
+      if (!(await hasTS(template))) {
         logger.error`Template name=${template} doesn't provide the Typescript variant.`;
         process.exit(1);
       }
@@ -279,7 +277,7 @@ export default async function init(
       logger.error`Copying Docusaurus template name=${template} failed!`;
       throw err;
     }
-  } else if (fs.existsSync(path.resolve(process.cwd(), template))) {
+  } else if (await fs.pathExists(path.resolve(process.cwd(), template))) {
     const templateDir = path.resolve(process.cwd(), template);
     try {
       await fs.copy(templateDir, dest);
@@ -306,13 +304,13 @@ export default async function init(
 
   // We need to rename the gitignore file to .gitignore
   if (
-    !fs.pathExistsSync(path.join(dest, '.gitignore')) &&
-    fs.pathExistsSync(path.join(dest, 'gitignore'))
+    !(await fs.pathExists(path.join(dest, '.gitignore'))) &&
+    (await fs.pathExists(path.join(dest, 'gitignore')))
   ) {
     await fs.move(path.join(dest, 'gitignore'), path.join(dest, '.gitignore'));
   }
-  if (fs.pathExistsSync(path.join(dest, 'gitignore'))) {
-    fs.removeSync(path.join(dest, 'gitignore'));
+  if (await fs.pathExists(path.join(dest, 'gitignore'))) {
+    await fs.remove(path.join(dest, 'gitignore'));
   }
 
   const pkgManager = useYarn ? 'yarn' : 'npm';
diff --git a/packages/docusaurus-mdx-loader/src/index.ts b/packages/docusaurus-mdx-loader/src/index.ts
index c3e15c338d..98690e146a 100644
--- a/packages/docusaurus-mdx-loader/src/index.ts
+++ b/packages/docusaurus-mdx-loader/src/index.ts
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {readFile} from 'fs-extra';
+import fs from 'fs-extra';
 import mdx from '@mdx-js/mdx';
 import logger from '@docusaurus/logger';
 import emoji from 'remark-emoji';
@@ -57,7 +57,7 @@ type Options = RemarkAndRehypePluginOptions & {
  */
 async function readMetadataPath(metadataPath: string) {
   try {
-    return await readFile(metadataPath, 'utf8');
+    return await fs.readFile(metadataPath, 'utf8');
   } catch (e) {
     throw new Error(
       `MDX loader can't read MDX metadata file for path ${metadataPath}. Maybe the isMDXPartial option function was not provided?`,
diff --git a/packages/docusaurus-mdx-loader/src/remark/toc/__tests__/index.test.ts b/packages/docusaurus-mdx-loader/src/remark/toc/__tests__/index.test.ts
index 53014375fa..f3134ef5d4 100644
--- a/packages/docusaurus-mdx-loader/src/remark/toc/__tests__/index.test.ts
+++ b/packages/docusaurus-mdx-loader/src/remark/toc/__tests__/index.test.ts
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {join} from 'path';
+import path from 'path';
 import remark from 'remark';
 import mdx from 'remark-mdx';
 import vfile from 'to-vfile';
@@ -13,8 +13,8 @@ import plugin from '../index';
 import headings from '../../headings/index';
 
 const processFixture = async (name, options?) => {
-  const path = join(__dirname, '__fixtures__', `${name}.md`);
-  const file = await vfile.read(path);
+  const filePath = path.join(__dirname, '__fixtures__', `${name}.md`);
+  const file = await vfile.read(filePath);
   const result = await remark()
     .use(headings)
     .use(mdx)
diff --git a/packages/docusaurus-migrate/src/__tests__/migration.test.ts b/packages/docusaurus-migrate/src/__tests__/migration.test.ts
index 4b0397f9e8..daf21ba47c 100644
--- a/packages/docusaurus-migrate/src/__tests__/migration.test.ts
+++ b/packages/docusaurus-migrate/src/__tests__/migration.test.ts
@@ -21,7 +21,7 @@ describe('migration test', () => {
     await expect(
       migrateDocusaurusProject(siteDir, newDir),
     ).resolves.toBeUndefined();
-    fs.removeSync(newDir);
+    await fs.remove(newDir);
   });
   test('complex website', async () => {
     const siteDir = path.join(
@@ -38,7 +38,7 @@ describe('migration test', () => {
     await expect(
       migrateDocusaurusProject(siteDir, newDir),
     ).resolves.toBeUndefined();
-    fs.removeSync(newDir);
+    await fs.remove(newDir);
   });
 
   test('missing versions', async () => {
@@ -56,6 +56,6 @@ describe('migration test', () => {
     await expect(
       migrateDocusaurusProject(siteDir, newDir),
     ).resolves.toBeUndefined();
-    fs.removeSync(newDir);
+    await fs.remove(newDir);
   });
 });
diff --git a/packages/docusaurus-migrate/src/index.ts b/packages/docusaurus-migrate/src/index.ts
index fc41d79675..dc16556a2c 100644
--- a/packages/docusaurus-migrate/src/index.ts
+++ b/packages/docusaurus-migrate/src/index.ts
@@ -25,18 +25,18 @@ import path from 'path';
 const DOCUSAURUS_VERSION = (importFresh('../package.json') as {version: string})
   .version;
 
-export function walk(dir: string): Array<string> {
-  let results: Array<string> = [];
-  const list = fs.readdirSync(dir);
-  list.forEach((file: string) => {
+async function walk(dir: string): Promise<string[]> {
+  const results: string[] = [];
+  const list = await fs.readdir(dir);
+  for (const file of list) {
     const fullPath = `${dir}/${file}`;
-    const stat = fs.statSync(fullPath);
+    const stat = await fs.stat(fullPath);
     if (stat && stat.isDirectory()) {
-      results = results.concat(walk(fullPath));
+      results.push(...(await walk(fullPath)));
     } else {
       results.push(fullPath);
     }
-  });
+  }
   return results;
 }
 
@@ -112,7 +112,7 @@ export async function migrateDocusaurusProject(
   }
   if (shouldMigratePages) {
     try {
-      createPages(migrationContext);
+      await createPages(migrationContext);
       logger.success(
         'Created new doc pages (check migration page for more details)',
       );
@@ -122,7 +122,7 @@ export async function migrateDocusaurusProject(
     }
   } else {
     try {
-      createDefaultLandingPage(migrationContext);
+      await createDefaultLandingPage(migrationContext);
       logger.success(
         'Created landing page (check migration page for more details)',
       );
@@ -133,41 +133,41 @@ export async function migrateDocusaurusProject(
   }
 
   try {
-    migrateStaticFiles(migrationContext);
+    await migrateStaticFiles(migrationContext);
     logger.success('Migrated static folder');
   } catch (e) {
     logger.error(`Failed to copy static folder: ${e}`);
     errorCount += 1;
   }
   try {
-    migrateBlogFiles(migrationContext);
+    await migrateBlogFiles(migrationContext);
   } catch (e) {
     logger.error(`Failed to migrate blogs: ${e}`);
     errorCount += 1;
   }
   try {
-    handleVersioning(migrationContext);
+    await handleVersioning(migrationContext);
   } catch (e) {
     logger.error(`Failed to migrate versioned docs: ${e}`);
     errorCount += 1;
   }
 
   try {
-    migrateLatestDocs(migrationContext);
+    await migrateLatestDocs(migrationContext);
   } catch (e) {
     logger.error(`Failed to migrate docs: ${e}`);
     errorCount += 1;
   }
 
   try {
-    migrateLatestSidebar(migrationContext);
+    await migrateLatestSidebar(migrationContext);
   } catch (e) {
     logger.error(`Failed to migrate sidebar: ${e}`);
     errorCount += 1;
   }
 
   try {
-    fs.writeFileSync(
+    await fs.writeFile(
       path.join(newDir, 'docusaurus.config.js'),
       `module.exports=${JSON.stringify(migrationContext.v2Config, null, 2)}`,
     );
@@ -368,33 +368,35 @@ function createClientRedirects(context: MigrationContext): void {
   }
 }
 
-function createPages(context: MigrationContext): void {
+async function createPages(context: MigrationContext) {
   const {newDir, siteDir} = context;
-  fs.mkdirpSync(path.join(newDir, 'src', 'pages'));
-  if (fs.existsSync(path.join(siteDir, 'pages', 'en'))) {
+  await fs.mkdirp(path.join(newDir, 'src', 'pages'));
+  if (await fs.pathExists(path.join(siteDir, 'pages', 'en'))) {
     try {
-      fs.copySync(
+      await fs.copy(
         path.join(siteDir, 'pages', 'en'),
         path.join(newDir, 'src', 'pages'),
       );
-      const files = Globby.sync('**/*.js', {
+      const files = await Globby('**/*.js', {
         cwd: path.join(newDir, 'src', 'pages'),
       });
-      files.forEach((file) => {
-        const filePath = path.join(newDir, 'src', 'pages', file);
-        const content = String(fs.readFileSync(filePath));
-        fs.writeFileSync(filePath, migratePage(content));
-      });
+      await Promise.all(
+        files.map(async (file) => {
+          const filePath = path.join(newDir, 'src', 'pages', file);
+          const content = await fs.readFile(filePath, 'utf-8');
+          await fs.writeFile(filePath, migratePage(content));
+        }),
+      );
     } catch (e) {
       logger.error(`Unable to migrate Pages: ${e}`);
-      createDefaultLandingPage(context);
+      await createDefaultLandingPage(context);
     }
   } else {
     logger.info('Ignoring Pages');
   }
 }
 
-function createDefaultLandingPage({newDir}: MigrationContext) {
+async function createDefaultLandingPage({newDir}: MigrationContext) {
   const indexPage = `import Layout from "@theme/Layout";
       import React from "react";
 
@@ -402,30 +404,32 @@ function createDefaultLandingPage({newDir}: MigrationContext) {
         return <Layout />;
       };
       `;
-  fs.mkdirpSync(`${newDir}/src/pages/`);
-  fs.writeFileSync(`${newDir}/src/pages/index.js`, indexPage);
+  await fs.mkdirp(`${newDir}/src/pages/`);
+  await fs.writeFile(`${newDir}/src/pages/index.js`, indexPage);
 }
 
-function migrateStaticFiles({siteDir, newDir}: MigrationContext): void {
-  if (fs.existsSync(path.join(siteDir, 'static'))) {
-    fs.copySync(path.join(siteDir, 'static'), path.join(newDir, 'static'));
+async function migrateStaticFiles({siteDir, newDir}: MigrationContext) {
+  if (await fs.pathExists(path.join(siteDir, 'static'))) {
+    await fs.copy(path.join(siteDir, 'static'), path.join(newDir, 'static'));
   } else {
-    fs.mkdirSync(path.join(newDir, 'static'));
+    await fs.mkdir(path.join(newDir, 'static'));
   }
 }
 
-function migrateBlogFiles(context: MigrationContext): void {
+async function migrateBlogFiles(context: MigrationContext) {
   const {siteDir, newDir, shouldMigrateMdFiles} = context;
-  if (fs.existsSync(path.join(siteDir, 'blog'))) {
-    fs.copySync(path.join(siteDir, 'blog'), path.join(newDir, 'blog'));
-    const files = walk(path.join(newDir, 'blog'));
-    files.forEach((file) => {
-      const content = String(fs.readFileSync(file));
-      fs.writeFileSync(
-        file,
-        sanitizedFileContent(content, shouldMigrateMdFiles),
-      );
-    });
+  if (await fs.pathExists(path.join(siteDir, 'blog'))) {
+    await fs.copy(path.join(siteDir, 'blog'), path.join(newDir, 'blog'));
+    const files = await walk(path.join(newDir, 'blog'));
+    await Promise.all(
+      files.map(async (file) => {
+        const content = await fs.readFile(file, 'utf-8');
+        await fs.writeFile(
+          file,
+          sanitizedFileContent(content, shouldMigrateMdFiles),
+        );
+      }),
+    );
     context.v2Config.presets[0][1].blog.path = 'blog';
     logger.success('Migrated blogs to version 2 with change in front matter');
   } else {
@@ -433,21 +437,21 @@ function migrateBlogFiles(context: MigrationContext): void {
   }
 }
 
-function handleVersioning(context: MigrationContext): void {
+async function handleVersioning(context: MigrationContext) {
   const {siteDir, newDir} = context;
-  if (fs.existsSync(path.join(siteDir, 'versions.json'))) {
-    const loadedVersions: Array<string> = JSON.parse(
-      String(fs.readFileSync(path.join(siteDir, 'versions.json'))),
+  if (await fs.pathExists(path.join(siteDir, 'versions.json'))) {
+    const loadedVersions: string[] = JSON.parse(
+      await fs.readFile(path.join(siteDir, 'versions.json'), 'utf-8'),
     );
-    fs.copyFileSync(
+    await fs.copyFile(
       path.join(siteDir, 'versions.json'),
       path.join(newDir, 'versions.json'),
     );
     const versions = loadedVersions.reverse();
     const versionRegex = new RegExp(`version-(${versions.join('|')})-`, 'mgi');
-    migrateVersionedSidebar(context, versions, versionRegex);
-    fs.mkdirpSync(path.join(newDir, 'versioned_docs'));
-    migrateVersionedDocs(context, versions, versionRegex);
+    await migrateVersionedSidebar(context, versions, versionRegex);
+    await fs.mkdirp(path.join(newDir, 'versioned_docs'));
+    await migrateVersionedDocs(context, versions, versionRegex);
     logger.success`Migrated version docs and sidebar. The following doc versions have been created:name=${loadedVersions}`;
   } else {
     logger.warn(
@@ -456,69 +460,78 @@ function handleVersioning(context: MigrationContext): void {
   }
 }
 
-function migrateVersionedDocs(
+async function migrateVersionedDocs(
   context: MigrationContext,
   versions: string[],
   versionRegex: RegExp,
-): void {
+) {
   const {siteDir, newDir, shouldMigrateMdFiles} = context;
-  versions.reverse().forEach((version, index) => {
-    if (index === 0) {
-      fs.copySync(
-        path.join(siteDir, '..', context.v1Config.customDocsPath || 'docs'),
-        path.join(newDir, 'versioned_docs', `version-${version}`),
-      );
-      fs.copySync(
-        path.join(siteDir, 'versioned_docs', `version-${version}`),
-        path.join(newDir, 'versioned_docs', `version-${version}`),
-      );
-      return;
-    }
-    try {
-      fs.mkdirsSync(path.join(newDir, 'versioned_docs', `version-${version}`));
-      fs.copySync(
-        path.join(newDir, 'versioned_docs', `version-${versions[index - 1]}`),
-        path.join(newDir, 'versioned_docs', `version-${version}`),
-      );
-      fs.copySync(
-        path.join(siteDir, 'versioned_docs', `version-${version}`),
-        path.join(newDir, 'versioned_docs', `version-${version}`),
-      );
-    } catch {
-      fs.copySync(
-        path.join(newDir, 'versioned_docs', `version-${versions[index - 1]}`),
-        path.join(newDir, 'versioned_docs', `version-${version}`),
-      );
-    }
-  });
-  const files = walk(path.join(newDir, 'versioned_docs'));
-  files.forEach((pathToFile) => {
-    if (path.extname(pathToFile) === '.md') {
-      const content = fs.readFileSync(pathToFile).toString();
-      fs.writeFileSync(
-        pathToFile,
-        sanitizedFileContent(
-          content.replace(versionRegex, ''),
-          shouldMigrateMdFiles,
-        ),
-      );
-    }
-  });
+  await Promise.all(
+    versions.reverse().map(async (version, index) => {
+      if (index === 0) {
+        await fs.copy(
+          path.join(siteDir, '..', context.v1Config.customDocsPath || 'docs'),
+          path.join(newDir, 'versioned_docs', `version-${version}`),
+        );
+        await fs.copy(
+          path.join(siteDir, 'versioned_docs', `version-${version}`),
+          path.join(newDir, 'versioned_docs', `version-${version}`),
+        );
+        return;
+      }
+      try {
+        await fs.mkdirs(
+          path.join(newDir, 'versioned_docs', `version-${version}`),
+        );
+        await fs.copy(
+          path.join(newDir, 'versioned_docs', `version-${versions[index - 1]}`),
+          path.join(newDir, 'versioned_docs', `version-${version}`),
+        );
+        await fs.copy(
+          path.join(siteDir, 'versioned_docs', `version-${version}`),
+          path.join(newDir, 'versioned_docs', `version-${version}`),
+        );
+      } catch {
+        await fs.copy(
+          path.join(newDir, 'versioned_docs', `version-${versions[index - 1]}`),
+          path.join(newDir, 'versioned_docs', `version-${version}`),
+        );
+      }
+    }),
+  );
+  const files = await walk(path.join(newDir, 'versioned_docs'));
+  await Promise.all(
+    files.map(async (pathToFile) => {
+      if (path.extname(pathToFile) === '.md') {
+        const content = await fs.readFile(pathToFile, 'utf-8');
+        await fs.writeFile(
+          pathToFile,
+          sanitizedFileContent(
+            content.replace(versionRegex, ''),
+            shouldMigrateMdFiles,
+          ),
+        );
+      }
+    }),
+  );
 }
 
-function migrateVersionedSidebar(
+async function migrateVersionedSidebar(
   context: MigrationContext,
   versions: string[],
   versionRegex: RegExp,
-): void {
+) {
   const {siteDir, newDir} = context;
-  if (fs.existsSync(path.join(siteDir, 'versioned_sidebars'))) {
-    fs.mkdirpSync(path.join(newDir, 'versioned_sidebars'));
+  if (await fs.pathExists(path.join(siteDir, 'versioned_sidebars'))) {
+    await fs.mkdirp(path.join(newDir, 'versioned_sidebars'));
     const sidebars: {
       entries: SidebarEntries;
       version: string;
     }[] = [];
-    versions.forEach((version, index) => {
+    // Order matters: if a sidebar file doesn't exist, we have to use the
+    // previous version's
+    for (let i = 0; i < versions.length; i += 1) {
+      const version = versions[i];
       let sidebarEntries: SidebarEntries;
       const sidebarPath = path.join(
         siteDir,
@@ -526,79 +539,74 @@ function migrateVersionedSidebar(
         `version-${version}-sidebars.json`,
       );
       try {
-        fs.statSync(sidebarPath);
-        sidebarEntries = JSON.parse(String(fs.readFileSync(sidebarPath)));
+        sidebarEntries = JSON.parse(await fs.readFile(sidebarPath, 'utf-8'));
       } catch {
-        sidebars.push({version, entries: sidebars[index - 1].entries});
+        sidebars.push({version, entries: sidebars[i - 1].entries});
         return;
       }
       const newSidebar = Object.entries(sidebarEntries).reduce(
         (topLevel: SidebarEntries, value) => {
           const key = value[0].replace(versionRegex, '');
-          topLevel[key] = Object.entries(value[1]).reduce(
-            (
-              acc: {[key: string]: Array<Record<string, unknown> | string>},
-              val,
-            ) => {
-              acc[val[0].replace(versionRegex, '')] = (
-                val[1] as Array<SidebarEntry>
-              ).map((item) => {
-                if (typeof item === 'string') {
-                  return item.replace(versionRegex, '');
-                }
-                return {
-                  type: 'category',
-                  label: item.label,
-                  ids: item.ids.map((id) => id.replace(versionRegex, '')),
-                };
-              });
-              return acc;
-            },
-            {},
-          );
+          topLevel[key] = Object.entries(value[1]).reduce((acc, val) => {
+            acc[val[0].replace(versionRegex, '')] = (
+              val[1] as SidebarEntry[]
+            ).map((item) => {
+              if (typeof item === 'string') {
+                return item.replace(versionRegex, '');
+              }
+              return {
+                type: 'category',
+                label: item.label,
+                ids: item.ids.map((id) => id.replace(versionRegex, '')),
+              };
+            });
+            return acc;
+          }, {} as Record<string, Array<string | Record<string, unknown>>>);
           return topLevel;
         },
         {},
       );
       sidebars.push({version, entries: newSidebar});
-    });
-    sidebars.forEach((sidebar) => {
-      const newSidebar = Object.entries(sidebar.entries).reduce(
-        (acc: SidebarEntries, val) => {
-          const key = `version-${sidebar.version}/${val[0]}`;
-          acc[key] = Object.entries(val[1]).map((value) => ({
-            type: 'category',
-            label: value[0],
-            items: (value[1] as Array<SidebarEntry>).map((sidebarItem) => {
-              if (typeof sidebarItem === 'string') {
+    }
+    await Promise.all(
+      sidebars.map(async (sidebar) => {
+        const newSidebar = Object.entries(sidebar.entries).reduce(
+          (acc, val) => {
+            const key = `version-${sidebar.version}/${val[0]}`;
+            acc[key] = Object.entries(val[1]).map((value) => ({
+              type: 'category',
+              label: value[0],
+              items: (value[1] as SidebarEntry[]).map((sidebarItem) => {
+                if (typeof sidebarItem === 'string') {
+                  return {
+                    type: 'doc',
+                    id: `version-${sidebar.version}/${sidebarItem}`,
+                  };
+                }
                 return {
-                  type: 'doc',
-                  id: `version-${sidebar.version}/${sidebarItem}`,
+                  type: 'category',
+                  label: sidebarItem.label,
+                  items: sidebarItem.ids.map((id) => ({
+                    type: 'doc',
+                    id: `version-${sidebar.version}/${id}`,
+                  })),
                 };
-              }
-              return {
-                type: 'category',
-                label: sidebarItem.label,
-                items: sidebarItem.ids.map((id: string) => ({
-                  type: 'doc',
-                  id: `version-${sidebar.version}/${id}`,
-                })),
-              };
-            }),
-          }));
-          return acc;
-        },
-        {},
-      );
-      fs.writeFileSync(
-        path.join(
-          newDir,
-          'versioned_sidebars',
-          `version-${sidebar.version}-sidebars.json`,
-        ),
-        JSON.stringify(newSidebar, null, 2),
-      );
-    });
+              }),
+            }));
+            return acc;
+          },
+          {} as SidebarEntries,
+        );
+        await fs.writeFile(
+          path.join(
+            newDir,
+            'versioned_sidebars',
+            `version-${sidebar.version}-sidebars.json`,
+          ),
+          JSON.stringify(newSidebar, null, 2),
+        );
+      }),
+    );
     context.v2Config.themeConfig.navbar.items.push({
       label: 'Version',
       to: 'docs',
@@ -626,10 +634,10 @@ function migrateVersionedSidebar(
   }
 }
 
-function migrateLatestSidebar(context: MigrationContext): void {
+async function migrateLatestSidebar(context: MigrationContext) {
   const {siteDir, newDir} = context;
   try {
-    fs.copyFileSync(
+    await fs.copyFile(
       path.join(siteDir, 'sidebars.json'),
       path.join(newDir, 'sidebars.json'),
     );
@@ -652,8 +660,8 @@ function migrateLatestSidebar(context: MigrationContext): void {
   --ifm-color-primary-darkest: ${primaryColor.darken(0.3).hex()};
 }
 `;
-    fs.mkdirpSync(path.join(newDir, 'src', 'css'));
-    fs.writeFileSync(path.join(newDir, 'src', 'css', 'customTheme.css'), css);
+    await fs.mkdirp(path.join(newDir, 'src', 'css'));
+    await fs.writeFile(path.join(newDir, 'src', 'css', 'customTheme.css'), css);
     context.v2Config.presets[0][1].theme.customCss = path.join(
       path.relative(newDir, path.join(siteDir, '..')),
       'src',
@@ -663,23 +671,25 @@ function migrateLatestSidebar(context: MigrationContext): void {
   }
 }
 
-function migrateLatestDocs(context: MigrationContext): void {
+async function migrateLatestDocs(context: MigrationContext) {
   const {siteDir, newDir, shouldMigrateMdFiles} = context;
-  if (fs.existsSync(path.join(siteDir, '..', 'docs'))) {
+  if (await fs.pathExists(path.join(siteDir, '..', 'docs'))) {
     context.v2Config.presets[0][1].docs.path = path.join(
       path.relative(newDir, path.join(siteDir, '..')),
       'docs',
     );
-    const files = walk(path.join(siteDir, '..', 'docs'));
-    files.forEach((file) => {
-      if (path.extname(file) === '.md') {
-        const content = fs.readFileSync(file).toString();
-        fs.writeFileSync(
-          file,
-          sanitizedFileContent(content, shouldMigrateMdFiles),
-        );
-      }
-    });
+    const files = await walk(path.join(siteDir, '..', 'docs'));
+    await Promise.all(
+      files.map(async (file) => {
+        if (path.extname(file) === '.md') {
+          const content = await fs.readFile(file, 'utf-8');
+          await fs.writeFile(
+            file,
+            sanitizedFileContent(content, shouldMigrateMdFiles),
+          );
+        }
+      }),
+    );
     logger.success('Migrated docs to version 2');
   } else {
     logger.warn('Docs folder not found. Skipping migration for docs');
@@ -713,7 +723,7 @@ async function migratePackageFile(context: MigrationContext): Promise<void> {
     ...packageFile.dependencies,
     ...deps,
   };
-  fs.writeFileSync(
+  await fs.writeFile(
     path.join(newDir, 'package.json'),
     JSON.stringify(packageFile, null, 2),
   );
@@ -724,14 +734,16 @@ export async function migrateMDToMDX(
   siteDir: string,
   newDir: string,
 ): Promise<void> {
-  fs.mkdirpSync(newDir);
-  fs.copySync(siteDir, newDir);
-  const files = walk(newDir);
-  files.forEach((filePath) => {
-    if (path.extname(filePath) === '.md') {
-      const content = fs.readFileSync(filePath).toString();
-      fs.writeFileSync(filePath, sanitizedFileContent(content, true));
-    }
-  });
+  await fs.mkdirp(newDir);
+  await fs.copy(siteDir, newDir);
+  const files = await walk(newDir);
+  await Promise.all(
+    files.map(async (filePath) => {
+      if (path.extname(filePath) === '.md') {
+        const content = await fs.readFile(filePath, 'utf-8');
+        await fs.writeFile(filePath, sanitizedFileContent(content, true));
+      }
+    }),
+  );
   logger.success`Successfully migrated path=${siteDir} to path=${newDir}`;
 }
diff --git a/packages/docusaurus-plugin-content-blog/src/__tests__/linkify.test.ts b/packages/docusaurus-plugin-content-blog/src/__tests__/linkify.test.ts
index 9fe9a51490..d745399331 100644
--- a/packages/docusaurus-plugin-content-blog/src/__tests__/linkify.test.ts
+++ b/packages/docusaurus-plugin-content-blog/src/__tests__/linkify.test.ts
@@ -43,8 +43,11 @@ const blogPosts: BlogPost[] = [
   },
 ];
 
-const transform = (filePath: string, options?: Partial<LinkifyParams>) => {
-  const fileContent = fs.readFileSync(filePath, 'utf-8');
+const transform = async (
+  filePath: string,
+  options?: Partial<LinkifyParams>,
+) => {
+  const fileContent = await fs.readFile(filePath, 'utf-8');
   const transformedContent = linkify({
     filePath,
     fileString: fileContent,
@@ -61,9 +64,9 @@ const transform = (filePath: string, options?: Partial<LinkifyParams>) => {
   return [fileContent, transformedContent];
 };
 
-test('transform to correct link', () => {
+test('transform to correct link', async () => {
   const post = path.join(contentPaths.contentPath, 'post.md');
-  const [content, transformedContent] = transform(post);
+  const [content, transformedContent] = await transform(post);
   expect(transformedContent).toMatchSnapshot();
   expect(transformedContent).toContain(
     '](/blog/2018/12/14/Happy-First-Birthday-Slash',
@@ -74,12 +77,12 @@ test('transform to correct link', () => {
   expect(content).not.toEqual(transformedContent);
 });
 
-test('report broken markdown links', () => {
+test('report broken markdown links', async () => {
   const filePath = 'post-with-broken-links.md';
   const folderPath = contentPaths.contentPath;
   const postWithBrokenLinks = path.join(folderPath, filePath);
   const onBrokenMarkdownLink = jest.fn();
-  const [, transformedContent] = transform(postWithBrokenLinks, {
+  const [, transformedContent] = await transform(postWithBrokenLinks, {
     onBrokenMarkdownLink,
   });
   expect(transformedContent).toMatchSnapshot();
diff --git a/packages/docusaurus-plugin-content-blog/src/blogUtils.ts b/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
index 94898473e8..0cfaf0f146 100644
--- a/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
+++ b/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
@@ -332,7 +332,7 @@ export async function generateBlogPosts(
 ): Promise<BlogPost[]> {
   const {include, exclude} = options;
 
-  if (!fs.existsSync(contentPaths.contentPath)) {
+  if (!(await fs.pathExists(contentPaths.contentPath))) {
     return [];
   }
 
diff --git a/packages/docusaurus-plugin-content-docs/src/__tests__/cli.test.ts b/packages/docusaurus-plugin-content-docs/src/__tests__/cli.test.ts
index 46fd8f0e92..e866f3099e 100644
--- a/packages/docusaurus-plugin-content-docs/src/__tests__/cli.test.ts
+++ b/packages/docusaurus-plugin-content-docs/src/__tests__/cli.test.ts
@@ -185,9 +185,9 @@ describe('docsVersion', () => {
   });
 
   test('first time versioning', async () => {
-    const copyMock = jest.spyOn(fs, 'copySync').mockImplementation();
-    const ensureMock = jest.spyOn(fs, 'ensureDirSync').mockImplementation();
-    const writeMock = jest.spyOn(fs, 'writeFileSync');
+    const copyMock = jest.spyOn(fs, 'copy').mockImplementation();
+    const ensureMock = jest.spyOn(fs, 'ensureDir').mockImplementation();
+    const writeMock = jest.spyOn(fs, 'writeFile');
     let versionedSidebar;
     let versionedSidebarPath;
     writeMock.mockImplementationOnce((filepath, content) => {
@@ -242,9 +242,9 @@ describe('docsVersion', () => {
   });
 
   test('not the first time versioning', async () => {
-    const copyMock = jest.spyOn(fs, 'copySync').mockImplementation();
-    const ensureMock = jest.spyOn(fs, 'ensureDirSync').mockImplementation();
-    const writeMock = jest.spyOn(fs, 'writeFileSync');
+    const copyMock = jest.spyOn(fs, 'copy').mockImplementation();
+    const ensureMock = jest.spyOn(fs, 'ensureDir').mockImplementation();
+    const writeMock = jest.spyOn(fs, 'writeFile');
     let versionedSidebar;
     let versionedSidebarPath;
     writeMock.mockImplementationOnce((filepath, content) => {
@@ -301,9 +301,9 @@ describe('docsVersion', () => {
   test('second docs instance versioning', async () => {
     const pluginId = 'community';
 
-    const copyMock = jest.spyOn(fs, 'copySync').mockImplementation();
-    const ensureMock = jest.spyOn(fs, 'ensureDirSync').mockImplementation();
-    const writeMock = jest.spyOn(fs, 'writeFileSync');
+    const copyMock = jest.spyOn(fs, 'copy').mockImplementation();
+    const ensureMock = jest.spyOn(fs, 'ensureDir').mockImplementation();
+    const writeMock = jest.spyOn(fs, 'writeFile');
     let versionedSidebar;
     let versionedSidebarPath;
     writeMock.mockImplementationOnce((filepath, content) => {
diff --git a/packages/docusaurus-plugin-content-docs/src/__tests__/lastUpdate.test.ts b/packages/docusaurus-plugin-content-docs/src/__tests__/lastUpdate.test.ts
index 6e90dc54d6..01356ccdcb 100644
--- a/packages/docusaurus-plugin-content-docs/src/__tests__/lastUpdate.test.ts
+++ b/packages/docusaurus-plugin-content-docs/src/__tests__/lastUpdate.test.ts
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import fs from 'fs';
+import fs from 'fs-extra';
 import path from 'path';
 import shell from 'shelljs';
 
@@ -64,9 +64,9 @@ describe('lastUpdate', () => {
 
   test('temporary created file that has no git timestamp', async () => {
     const tempFilePath = path.join(__dirname, '__fixtures__', '.temp');
-    fs.writeFileSync(tempFilePath, 'Lorem ipsum :)');
+    await fs.writeFile(tempFilePath, 'Lorem ipsum :)');
     await expect(getFileLastUpdate(tempFilePath)).resolves.toBeNull();
-    fs.unlinkSync(tempFilePath);
+    await fs.unlink(tempFilePath);
   });
 
   test('Git does not exist', async () => {
diff --git a/packages/docusaurus-plugin-content-docs/src/cli.ts b/packages/docusaurus-plugin-content-docs/src/cli.ts
index a4cf9ee054..fea26eae58 100644
--- a/packages/docusaurus-plugin-content-docs/src/cli.ts
+++ b/packages/docusaurus-plugin-content-docs/src/cli.ts
@@ -47,8 +47,8 @@ async function createVersionedSidebarFile({
       versionedSidebarsDir,
       `version-${version}-sidebars.json`,
     );
-    fs.ensureDirSync(path.dirname(newSidebarFile));
-    fs.writeFileSync(
+    await fs.ensureDir(path.dirname(newSidebarFile));
+    await fs.writeFile(
       newSidebarFile,
       `${JSON.stringify(sidebars, null, 2)}\n`,
       'utf8',
@@ -104,8 +104,8 @@ export async function cliDocsVersionCommand(
   // Load existing versions.
   let versions = [];
   const versionsJSONFile = getVersionsFilePath(siteDir, pluginId);
-  if (fs.existsSync(versionsJSONFile)) {
-    versions = JSON.parse(fs.readFileSync(versionsJSONFile, 'utf8'));
+  if (await fs.pathExists(versionsJSONFile)) {
+    versions = JSON.parse(await fs.readFile(versionsJSONFile, 'utf8'));
   }
 
   // Check if version already exists.
@@ -120,10 +120,13 @@ export async function cliDocsVersionCommand(
   // Copy docs files.
   const docsDir = path.join(siteDir, docsPath);
 
-  if (fs.existsSync(docsDir) && fs.readdirSync(docsDir).length > 0) {
+  if (
+    (await fs.pathExists(docsDir)) &&
+    (await fs.readdir(docsDir)).length > 0
+  ) {
     const versionedDir = getVersionedDocsDirPath(siteDir, pluginId);
     const newVersionDir = path.join(versionedDir, `version-${version}`);
-    fs.copySync(docsDir, newVersionDir);
+    await fs.copy(docsDir, newVersionDir);
   } else {
     throw new Error(`${pluginIdLogPrefix}: there is no docs to version!`);
   }
@@ -137,8 +140,11 @@ export async function cliDocsVersionCommand(
 
   // Update versions.json file.
   versions.unshift(version);
-  fs.ensureDirSync(path.dirname(versionsJSONFile));
-  fs.writeFileSync(versionsJSONFile, `${JSON.stringify(versions, null, 2)}\n`);
+  await fs.ensureDir(path.dirname(versionsJSONFile));
+  await fs.writeFile(
+    versionsJSONFile,
+    `${JSON.stringify(versions, null, 2)}\n`,
+  );
 
   logger.success`name=${pluginIdLogPrefix}: version name=${version} created!`;
 }
diff --git a/packages/docusaurus-plugin-content-docs/src/markdown/__tests__/linkify.test.ts b/packages/docusaurus-plugin-content-docs/src/markdown/__tests__/linkify.test.ts
index 56dc2cc9e9..79c2fc91f5 100644
--- a/packages/docusaurus-plugin-content-docs/src/markdown/__tests__/linkify.test.ts
+++ b/packages/docusaurus-plugin-content-docs/src/markdown/__tests__/linkify.test.ts
@@ -89,23 +89,26 @@ function createMarkdownOptions(
   };
 }
 
-const transform = (filepath: string, options?: Partial<DocsMarkdownOption>) => {
+const transform = async (
+  filepath: string,
+  options?: Partial<DocsMarkdownOption>,
+) => {
   const markdownOptions = createMarkdownOptions(options);
-  const content = fs.readFileSync(filepath, 'utf-8');
+  const content = await fs.readFile(filepath, 'utf-8');
   const transformedContent = linkify(content, filepath, markdownOptions);
   return [content, transformedContent];
 };
 
-test('transform nothing', () => {
+test('transform nothing', async () => {
   const doc1 = path.join(versionCurrent.contentPath, 'doc1.md');
-  const [content, transformedContent] = transform(doc1);
+  const [content, transformedContent] = await transform(doc1);
   expect(transformedContent).toMatchSnapshot();
   expect(content).toEqual(transformedContent);
 });
 
-test('transform to correct links', () => {
+test('transform to correct links', async () => {
   const doc2 = path.join(versionCurrent.contentPath, 'doc2.md');
-  const [content, transformedContent] = transform(doc2);
+  const [content, transformedContent] = await transform(doc2);
   expect(transformedContent).toMatchSnapshot();
   expect(transformedContent).toContain('](/docs/doc1');
   expect(transformedContent).toContain('](/docs/doc2');
@@ -118,19 +121,19 @@ test('transform to correct links', () => {
   expect(content).not.toEqual(transformedContent);
 });
 
-test('transform relative links', () => {
+test('transform relative links', async () => {
   const doc3 = path.join(versionCurrent.contentPath, 'subdir', 'doc3.md');
 
-  const [content, transformedContent] = transform(doc3);
+  const [content, transformedContent] = await transform(doc3);
   expect(transformedContent).toMatchSnapshot();
   expect(transformedContent).toContain('](/docs/doc2');
   expect(transformedContent).not.toContain('](../doc2.md)');
   expect(content).not.toEqual(transformedContent);
 });
 
-test('transforms reference links', () => {
+test('transforms reference links', async () => {
   const doc4 = path.join(versionCurrent.contentPath, 'doc4.md');
-  const [content, transformedContent] = transform(doc4);
+  const [content, transformedContent] = await transform(doc4);
   expect(transformedContent).toMatchSnapshot();
   expect(transformedContent).toContain('[doc1]: /docs/doc1');
   expect(transformedContent).toContain('[doc2]: /docs/doc2');
@@ -139,10 +142,10 @@ test('transforms reference links', () => {
   expect(content).not.toEqual(transformedContent);
 });
 
-test('report broken markdown links', () => {
+test('report broken markdown links', async () => {
   const doc5 = path.join(versionCurrent.contentPath, 'doc5.md');
   const onBrokenMarkdownLink = jest.fn();
-  const [content, transformedContent] = transform(doc5, {
+  const [content, transformedContent] = await transform(doc5, {
     onBrokenMarkdownLink,
   });
   expect(transformedContent).toEqual(content);
@@ -169,9 +172,9 @@ test('report broken markdown links', () => {
   } as BrokenMarkdownLink);
 });
 
-test('transforms absolute links in versioned docs', () => {
+test('transforms absolute links in versioned docs', async () => {
   const doc2 = path.join(version100.contentPath, 'doc2.md');
-  const [content, transformedContent] = transform(doc2);
+  const [content, transformedContent] = await transform(doc2);
   expect(transformedContent).toMatchSnapshot();
   expect(transformedContent).toContain('](/docs/1.0.0/subdir/doc1');
   expect(transformedContent).toContain('](/docs/1.0.0/doc2#existing-docs');
@@ -180,9 +183,9 @@ test('transforms absolute links in versioned docs', () => {
   expect(content).not.toEqual(transformedContent);
 });
 
-test('transforms relative links in versioned docs', () => {
+test('transforms relative links in versioned docs', async () => {
   const doc1 = path.join(version100.contentPath, 'subdir', 'doc1.md');
-  const [content, transformedContent] = transform(doc1);
+  const [content, transformedContent] = await transform(doc1);
   expect(transformedContent).toMatchSnapshot();
   expect(transformedContent).toContain('](/docs/1.0.0/doc2');
   expect(transformedContent).not.toContain('](../doc2.md)');
diff --git a/packages/docusaurus-plugin-content-docs/src/sidebars/index.ts b/packages/docusaurus-plugin-content-docs/src/sidebars/index.ts
index bdb65f73f7..b57822b5dd 100644
--- a/packages/docusaurus-plugin-content-docs/src/sidebars/index.ts
+++ b/packages/docusaurus-plugin-content-docs/src/sidebars/index.ts
@@ -85,7 +85,7 @@ export async function loadSidebarsFileUnsafe(
   // Non-existent sidebars file: no sidebars
   // Note: this edge case can happen on versioned docs, not current version
   // We avoid creating empty versioned sidebars file with the CLI
-  if (!fs.existsSync(sidebarFilePath)) {
+  if (!(await fs.pathExists(sidebarFilePath))) {
     return DisabledSidebars;
   }
 
diff --git a/packages/docusaurus-plugin-content-docs/src/versions.ts b/packages/docusaurus-plugin-content-docs/src/versions.ts
index f886a93189..52d1c476bf 100644
--- a/packages/docusaurus-plugin-content-docs/src/versions.ts
+++ b/packages/docusaurus-plugin-content-docs/src/versions.ts
@@ -418,7 +418,7 @@ function createVersionMetadata({
   };
 }
 
-function checkVersionMetadataPaths({
+async function checkVersionMetadataPaths({
   versionMetadata,
   context,
 }: {
@@ -429,7 +429,7 @@ function checkVersionMetadataPaths({
   const {siteDir} = context;
   const isCurrentVersion = versionName === CURRENT_VERSION_NAME;
 
-  if (!fs.existsSync(contentPath)) {
+  if (!(await fs.pathExists(contentPath))) {
     throw new Error(
       `The docs folder does not exist for version "${versionName}". A docs folder is expected to be found at ${path.relative(
         siteDir,
@@ -446,7 +446,7 @@ function checkVersionMetadataPaths({
   if (
     isCurrentVersion &&
     typeof sidebarFilePath === 'string' &&
-    !fs.existsSync(sidebarFilePath)
+    !(await fs.pathExists(sidebarFilePath))
   ) {
     throw new Error(`The path to the sidebar file does not exist at "${path.relative(
       siteDir,
@@ -585,8 +585,10 @@ export async function readVersionsMetadata({
       options,
     }),
   );
-  versionsMetadata.forEach((versionMetadata) =>
-    checkVersionMetadataPaths({versionMetadata, context}),
+  await Promise.all(
+    versionsMetadata.map((versionMetadata) =>
+      checkVersionMetadataPaths({versionMetadata, context}),
+    ),
   );
   return versionsMetadata;
 }
diff --git a/packages/docusaurus-theme-search-algolia/package.json b/packages/docusaurus-theme-search-algolia/package.json
index a0e2376278..ba52707baa 100644
--- a/packages/docusaurus-theme-search-algolia/package.json
+++ b/packages/docusaurus-theme-search-algolia/package.json
@@ -36,13 +36,13 @@
     "algoliasearch-helper": "^3.7.0",
     "clsx": "^1.1.1",
     "eta": "^1.12.3",
+    "fs-extra": "^10.0.0",
     "lodash": "^4.17.21",
     "tslib": "^2.3.1",
     "utility-types": "^3.10.0"
   },
   "devDependencies": {
-    "@docusaurus/module-type-aliases": "2.0.0-beta.15",
-    "fs-extra": "^10.0.0"
+    "@docusaurus/module-type-aliases": "2.0.0-beta.15"
   },
   "peerDependencies": {
     "react": "^16.8.4 || ^17.0.0",
diff --git a/packages/docusaurus-theme-search-algolia/src/index.ts b/packages/docusaurus-theme-search-algolia/src/index.ts
index 1e38a7a898..4cb9597229 100644
--- a/packages/docusaurus-theme-search-algolia/src/index.ts
+++ b/packages/docusaurus-theme-search-algolia/src/index.ts
@@ -6,7 +6,7 @@
  */
 
 import path from 'path';
-import fs from 'fs';
+import fs from 'fs-extra';
 import {defaultConfig, compile} from 'eta';
 import {normalizeUrl} from '@docusaurus/utils';
 import {readDefaultCodeTranslationMessages} from '@docusaurus/theme-translations';
@@ -76,7 +76,7 @@ export default function themeSearchAlgolia(context: LoadContext): Plugin<void> {
         const siteUrl = normalizeUrl([url, baseUrl]);
 
         try {
-          fs.writeFileSync(
+          await fs.writeFile(
             path.join(outDir, OPEN_SEARCH_FILENAME),
             renderOpenSearchTemplate({
               title,
diff --git a/packages/docusaurus-theme-translations/update.js b/packages/docusaurus-theme-translations/update.js
index e1570edb9a..36ab30805c 100644
--- a/packages/docusaurus-theme-translations/update.js
+++ b/packages/docusaurus-theme-translations/update.js
@@ -6,7 +6,8 @@
  */
 
 // @ts-check
-/* eslint-disable import/no-extraneous-dependencies */
+// TODO convert this to ESM, which would also allow TLA
+/* eslint-disable import/no-extraneous-dependencies, no-restricted-properties */
 
 const logger = require('@docusaurus/logger').default;
 const path = require('path');
diff --git a/packages/docusaurus-utils/src/__tests__/index.test.ts b/packages/docusaurus-utils/src/__tests__/index.test.ts
index 6b84a8b5d6..8dbc0bc117 100644
--- a/packages/docusaurus-utils/src/__tests__/index.test.ts
+++ b/packages/docusaurus-utils/src/__tests__/index.test.ts
@@ -143,7 +143,7 @@ describe('load utils', () => {
 describe('generate', () => {
   test('behaves correctly', async () => {
     const writeMock = jest.spyOn(fs, 'writeFile').mockImplementation(() => {});
-    const existsMock = jest.spyOn(fs, 'existsSync');
+    const existsMock = jest.spyOn(fs, 'pathExists');
     const readMock = jest.spyOn(fs, 'readFile');
 
     // First call: no file, no cache
diff --git a/packages/docusaurus-utils/src/index.ts b/packages/docusaurus-utils/src/index.ts
index 2ae82d7bbb..7dd103f9d0 100644
--- a/packages/docusaurus-utils/src/index.ts
+++ b/packages/docusaurus-utils/src/index.ts
@@ -106,7 +106,7 @@ export async function generate(
   // If file already exists but its not in runtime cache yet,
   // we try to calculate the content hash and then compare
   // This is to avoid unnecessary overwriting and we can reuse old file.
-  if (!lastHash && fs.existsSync(filepath)) {
+  if (!lastHash && (await fs.pathExists(filepath))) {
     const lastContent = await fs.readFile(filepath, 'utf8');
     lastHash = createHash('md5').update(lastContent).digest('hex');
     fileHash.set(filepath, lastHash);
diff --git a/packages/docusaurus/bin/beforeCli.mjs b/packages/docusaurus/bin/beforeCli.mjs
index b4ec0dd456..5043f4073d 100644
--- a/packages/docusaurus/bin/beforeCli.mjs
+++ b/packages/docusaurus/bin/beforeCli.mjs
@@ -36,7 +36,7 @@ const {
  *
  * cache data is stored in `~/.config/configstore/update-notifier-@docusaurus`
  */
-function beforeCli() {
+async function beforeCli() {
   const notifier = updateNotifier({
     pkg: {
       name,
@@ -98,7 +98,9 @@ function beforeCli() {
       .filter((p) => p.startsWith('@docusaurus'))
       .map((p) => p.concat('@latest'))
       .join(' ');
-    const isYarnUsed = fs.existsSync(path.resolve(process.cwd(), 'yarn.lock'));
+    const isYarnUsed = await fs.pathExists(
+      path.resolve(process.cwd(), 'yarn.lock'),
+    );
     const upgradeCommand = isYarnUsed
       ? `yarn upgrade ${siteDocusaurusPackagesForUpdate}`
       : `npm i ${siteDocusaurusPackagesForUpdate}`;
diff --git a/packages/docusaurus/bin/docusaurus.mjs b/packages/docusaurus/bin/docusaurus.mjs
index 99798420f6..410f95f249 100755
--- a/packages/docusaurus/bin/docusaurus.mjs
+++ b/packages/docusaurus/bin/docusaurus.mjs
@@ -9,7 +9,7 @@
 // @ts-check
 
 import logger from '@docusaurus/logger';
-import fs from 'fs';
+import fs from 'fs-extra';
 import cli from 'commander';
 import {createRequire} from 'module';
 import {
@@ -25,9 +25,9 @@ import {
 } from '../lib/index.js';
 import beforeCli from './beforeCli.mjs';
 
-beforeCli();
+await beforeCli();
 
-const resolveDir = (dir = '.') => fs.realpathSync(dir);
+const resolveDir = (dir = '.') => fs.realpath(dir);
 
 cli
   .version(createRequire(import.meta.url)('../package.json').version)
@@ -56,8 +56,8 @@ cli
     '--no-minify',
     'build website without minimizing JS bundles (default: false)',
   )
-  .action((siteDir, {bundleAnalyzer, config, outDir, locale, minify}) => {
-    build(resolveDir(siteDir), {
+  .action(async (siteDir, {bundleAnalyzer, config, outDir, locale, minify}) => {
+    build(await resolveDir(siteDir), {
       bundleAnalyzer,
       outDir,
       config,
@@ -74,8 +74,14 @@ cli
     'copy TypeScript theme files when possible (default: false)',
   )
   .option('--danger', 'enable swizzle for internal component of themes')
-  .action((themeName, componentName, siteDir, {typescript, danger}) => {
-    swizzle(resolveDir(siteDir), themeName, componentName, typescript, danger);
+  .action(async (themeName, componentName, siteDir, {typescript, danger}) => {
+    swizzle(
+      await resolveDir(siteDir),
+      themeName,
+      componentName,
+      typescript,
+      danger,
+    );
   });
 
 cli
@@ -97,8 +103,8 @@ cli
     '--skip-build',
     'skip building website before deploy it (default: false)',
   )
-  .action((siteDir, {outDir, skipBuild, config}) => {
-    deploy(resolveDir(siteDir), {
+  .action(async (siteDir, {outDir, skipBuild, config}) => {
+    deploy(await resolveDir(siteDir), {
       outDir,
       config,
       skipBuild,
@@ -124,17 +130,19 @@ cli
     '--poll [interval]',
     'use polling rather than watching for reload (default: false). Can specify a poll interval in milliseconds',
   )
-  .action((siteDir, {port, host, locale, config, hotOnly, open, poll}) => {
-    start(resolveDir(siteDir), {
-      port,
-      host,
-      locale,
-      config,
-      hotOnly,
-      open,
-      poll,
-    });
-  });
+  .action(
+    async (siteDir, {port, host, locale, config, hotOnly, open, poll}) => {
+      start(await resolveDir(siteDir), {
+        port,
+        host,
+        locale,
+        config,
+        hotOnly,
+        open,
+        poll,
+      });
+    },
+  );
 
 cli
   .command('serve [siteDir]')
@@ -151,7 +159,7 @@ cli
   .option('--build', 'build website before serving (default: false)')
   .option('-h, --host <host>', 'use specified host (default: localhost)')
   .action(
-    (
+    async (
       siteDir,
       {
         dir = 'build',
@@ -161,7 +169,7 @@ cli
         config,
       },
     ) => {
-      serve(resolveDir(siteDir), {
+      serve(await resolveDir(siteDir), {
         dir,
         port,
         build: buildSite,
@@ -174,8 +182,8 @@ cli
 cli
   .command('clear [siteDir]')
   .description('Remove build artifacts.')
-  .action((siteDir) => {
-    clear(resolveDir(siteDir));
+  .action(async (siteDir) => {
+    clear(await resolveDir(siteDir));
   });
 
 cli
@@ -198,11 +206,11 @@ cli
     'allows to init new written messages with a given prefix. This might help you to highlight untranslated message to make them stand out in the UI',
   )
   .action(
-    (
+    async (
       siteDir,
       {locale = undefined, override = false, messagePrefix = '', config},
     ) => {
-      writeTranslations(resolveDir(siteDir), {
+      writeTranslations(await resolveDir(siteDir), {
         locale,
         override,
         config,
@@ -219,8 +227,8 @@ cli
     "keep the headings' casing, otherwise make all lowercase (default: false)",
   )
   .option('--overwrite', 'overwrite existing heading IDs (default: false)')
-  .action((siteDir, files, options) =>
-    writeHeadingIds(resolveDir(siteDir), files, options),
+  .action(async (siteDir, files, options) =>
+    writeHeadingIds(await resolveDir(siteDir), files, options),
   );
 
 cli.arguments('<command>').action((cmd) => {
@@ -246,7 +254,7 @@ function isInternalCommand(command) {
 
 async function run() {
   if (!isInternalCommand(process.argv.slice(2)[0])) {
-    await externalCommand(cli, resolveDir('.'));
+    await externalCommand(cli, await resolveDir('.'));
   }
 
   cli.parse(process.argv);
diff --git a/packages/docusaurus/package.json b/packages/docusaurus/package.json
index c361d0c5d1..64ac317006 100644
--- a/packages/docusaurus/package.json
+++ b/packages/docusaurus/package.json
@@ -56,6 +56,7 @@
     "boxen": "^5.1.2",
     "chokidar": "^3.5.3",
     "clean-css": "^5.2.4",
+    "combine-promises": "^1.1.0",
     "commander": "^5.1.0",
     "copy-webpack-plugin": "^10.2.4",
     "core-js": "^3.21.1",
diff --git a/packages/docusaurus/src/commands/build.ts b/packages/docusaurus/src/commands/build.ts
index 916515f8b0..e1ad88e567 100644
--- a/packages/docusaurus/src/commands/build.ts
+++ b/packages/docusaurus/src/commands/build.ts
@@ -130,7 +130,7 @@ async function buildLocale({
     'client-manifest.json',
   );
   let clientConfig: Configuration = merge(
-    createClientConfig(props, cliOptions.minify),
+    await createClientConfig(props, cliOptions.minify),
     {
       plugins: [
         // Remove/clean build folders before building bundles.
@@ -148,23 +148,26 @@ async function buildLocale({
 
   const allCollectedLinks: Record<string, string[]> = {};
 
-  let serverConfig: Configuration = createServerConfig({
+  let serverConfig: Configuration = await createServerConfig({
     props,
     onLinksCollected: (staticPagePath, links) => {
       allCollectedLinks[staticPagePath] = links;
     },
   });
 
-  serverConfig = merge(serverConfig, {
-    plugins: [
-      new CopyWebpackPlugin({
-        patterns: staticDirectories
-          .map((dir) => path.resolve(siteDir, dir))
-          .filter(fs.existsSync)
-          .map((dir) => ({from: dir, to: outDir})),
-      }),
-    ],
-  });
+  if (staticDirectories.length > 0) {
+    await Promise.all(staticDirectories.map((dir) => fs.ensureDir(dir)));
+
+    serverConfig = merge(serverConfig, {
+      plugins: [
+        new CopyWebpackPlugin({
+          patterns: staticDirectories
+            .map((dir) => path.resolve(siteDir, dir))
+            .map((dir) => ({from: dir, to: outDir})),
+        }),
+      ],
+    });
+  }
 
   // Plugin Lifecycle - configureWebpack and configurePostCss.
   plugins.forEach((plugin) => {
diff --git a/packages/docusaurus/src/commands/start.ts b/packages/docusaurus/src/commands/start.ts
index 706ff325a3..4a02bdf57b 100644
--- a/packages/docusaurus/src/commands/start.ts
+++ b/packages/docusaurus/src/commands/start.ts
@@ -107,7 +107,7 @@ export default async function start(
       ? (cliOptions.poll as number)
       : undefined,
   };
-  const httpsConfig = getHttpsConfig();
+  const httpsConfig = await getHttpsConfig();
   const fsWatcher = chokidar.watch(pathsToWatch, {
     cwd: siteDir,
     ignoreInitial: true,
@@ -118,7 +118,7 @@ export default async function start(
     fsWatcher.on(event, reload),
   );
 
-  let config: webpack.Configuration = merge(createClientConfig(props), {
+  let config: webpack.Configuration = merge(await createClientConfig(props), {
     infrastructureLogging: {
       // Reduce log verbosity, see https://github.com/facebook/docusaurus/pull/5420#issuecomment-906613105
       level: 'warn',
diff --git a/packages/docusaurus/src/commands/swizzle.ts b/packages/docusaurus/src/commands/swizzle.ts
index bba9dc90ef..95580cdfd4 100644
--- a/packages/docusaurus/src/commands/swizzle.ts
+++ b/packages/docusaurus/src/commands/swizzle.ts
@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+/* eslint-disable no-restricted-properties */
 import logger from '@docusaurus/logger';
 import fs from 'fs-extra';
 import importFresh from 'import-fresh';
diff --git a/packages/docusaurus/src/commands/writeTranslations.ts b/packages/docusaurus/src/commands/writeTranslations.ts
index 9d7cdfe3b6..017225bdf1 100644
--- a/packages/docusaurus/src/commands/writeTranslations.ts
+++ b/packages/docusaurus/src/commands/writeTranslations.ts
@@ -97,7 +97,7 @@ Available locales are: ${context.i18n.locales.join(',')}.`,
 
   const babelOptions = getBabelOptions({
     isServer: true,
-    babelOptions: getCustomBabelConfigFilePath(siteDir),
+    babelOptions: await getCustomBabelConfigFilePath(siteDir),
   });
   const extractedCodeTranslations = await extractSiteSourceCodeTranslations(
     siteDir,
diff --git a/packages/docusaurus/src/server/brokenLinks.ts b/packages/docusaurus/src/server/brokenLinks.ts
index 84bc87c810..0f8a51e122 100644
--- a/packages/docusaurus/src/server/brokenLinks.ts
+++ b/packages/docusaurus/src/server/brokenLinks.ts
@@ -20,6 +20,7 @@ import {
 } from '@docusaurus/utils';
 import {getAllFinalRoutes} from './utils';
 import path from 'path';
+import combinePromises from 'combine-promises';
 
 function toReactRouterRoutes(routes: RouteConfig[]): RRRouteConfig[] {
   // @ts-expect-error: types incompatible???
@@ -158,9 +159,9 @@ export function getBrokenLinksErrorMessage(
   );
 }
 
-function isExistingFile(filePath: string) {
+async function isExistingFile(filePath: string) {
   try {
-    return fs.statSync(filePath).isFile();
+    return (await fs.stat(filePath)).isFile();
   } catch (e) {
     return false;
   }
@@ -177,8 +178,7 @@ export async function filterExistingFileLinks({
   outDir: string;
   allCollectedLinks: Record<string, string[]>;
 }): Promise<Record<string, string[]>> {
-  // not easy to make this async :'(
-  function linkFileExists(link: string): boolean {
+  async function linkFileExists(link: string) {
     // /baseUrl/javadoc/ -> /outDir/javadoc
     const baseFilePath = removeSuffix(
       `${outDir}/${removePrefix(link, baseUrl)}`,
@@ -194,11 +194,22 @@ export async function filterExistingFileLinks({
       filePathsToTry.push(path.join(baseFilePath, 'index.html'));
     }
 
-    return filePathsToTry.some(isExistingFile);
+    for (const file of filePathsToTry) {
+      if (await isExistingFile(file)) {
+        return true;
+      }
+    }
+    return false;
   }
 
-  return _.mapValues(allCollectedLinks, (links) =>
-    links.filter((link) => !linkFileExists(link)),
+  return combinePromises(
+    _.mapValues(allCollectedLinks, async (links) =>
+      (
+        await Promise.all(
+          links.map(async (link) => ((await linkFileExists(link)) ? '' : link)),
+        )
+      ).filter(Boolean),
+    ),
   );
 }
 
diff --git a/packages/docusaurus/src/server/config.ts b/packages/docusaurus/src/server/config.ts
index 53bfec0a95..5f6d0ef01f 100644
--- a/packages/docusaurus/src/server/config.ts
+++ b/packages/docusaurus/src/server/config.ts
@@ -13,7 +13,7 @@ import {validateConfig} from './configValidation';
 export default async function loadConfig(
   configPath: string,
 ): Promise<DocusaurusConfig> {
-  if (!fs.existsSync(configPath)) {
+  if (!(await fs.pathExists(configPath))) {
     throw new Error(`Config file at "${configPath}" not found.`);
   }
 
diff --git a/packages/docusaurus/src/server/index.ts b/packages/docusaurus/src/server/index.ts
index 88a2c022ce..79e38c2549 100644
--- a/packages/docusaurus/src/server/index.ts
+++ b/packages/docusaurus/src/server/index.ts
@@ -403,10 +403,12 @@ ${Object.keys(registry)
 
   // Version metadata.
   const siteMetadata: DocusaurusSiteMetadata = {
-    docusaurusVersion: getPackageJsonVersion(
+    docusaurusVersion: (await getPackageJsonVersion(
       path.join(__dirname, '../../package.json'),
-    )!,
-    siteVersion: getPackageJsonVersion(path.join(siteDir, 'package.json')),
+    ))!,
+    siteVersion: await getPackageJsonVersion(
+      path.join(siteDir, 'package.json'),
+    ),
     pluginVersions: {},
   };
   plugins
diff --git a/packages/docusaurus/src/server/plugins/init.ts b/packages/docusaurus/src/server/plugins/init.ts
index 2ec1265fb7..bca734d302 100644
--- a/packages/docusaurus/src/server/plugins/init.ts
+++ b/packages/docusaurus/src/server/plugins/init.ts
@@ -133,9 +133,9 @@ export default async function initPlugins({
   // siteDir's package.json declares the dependency on these plugins.
   const pluginRequire = createRequire(context.siteConfigPath);
 
-  function doGetPluginVersion(
+  async function doGetPluginVersion(
     normalizedPluginConfig: NormalizedPluginConfig,
-  ): DocusaurusPluginVersionInformation {
+  ): Promise<DocusaurusPluginVersionInformation> {
     // get plugin version
     if (normalizedPluginConfig.pluginModule?.path) {
       const pluginPath = pluginRequire.resolve(
@@ -187,7 +187,7 @@ export default async function initPlugins({
       pluginRequire,
     );
     const pluginVersion: DocusaurusPluginVersionInformation =
-      doGetPluginVersion(normalizedPluginConfig);
+      await doGetPluginVersion(normalizedPluginConfig);
     const pluginOptions = doValidatePluginOptions(normalizedPluginConfig);
 
     // Side-effect: merge the normalized theme config in the original one
diff --git a/packages/docusaurus/src/server/themes/__tests__/alias.test.ts b/packages/docusaurus/src/server/themes/__tests__/alias.test.ts
index d64e3e5b39..dd140c3ee1 100644
--- a/packages/docusaurus/src/server/themes/__tests__/alias.test.ts
+++ b/packages/docusaurus/src/server/themes/__tests__/alias.test.ts
@@ -10,10 +10,10 @@ import fs from 'fs-extra';
 import themeAlias from '../alias';
 
 describe('themeAlias', () => {
-  test('valid themePath 1 with components', () => {
+  test('valid themePath 1 with components', async () => {
     const fixtures = path.join(__dirname, '__fixtures__');
     const themePath = path.join(fixtures, 'theme-1');
-    const alias = themeAlias(themePath, true);
+    const alias = await themeAlias(themePath, true);
     // Testing entries, because order matters!
     expect(Object.entries(alias)).toEqual(
       Object.entries({
@@ -26,10 +26,10 @@ describe('themeAlias', () => {
     expect(alias).not.toEqual({});
   });
 
-  test('valid themePath 1 with components without original', () => {
+  test('valid themePath 1 with components without original', async () => {
     const fixtures = path.join(__dirname, '__fixtures__');
     const themePath = path.join(fixtures, 'theme-1');
-    const alias = themeAlias(themePath, false);
+    const alias = await themeAlias(themePath, false);
     // Testing entries, because order matters!
     expect(Object.entries(alias)).toEqual(
       Object.entries({
@@ -40,10 +40,10 @@ describe('themeAlias', () => {
     expect(alias).not.toEqual({});
   });
 
-  test('valid themePath 2 with components', () => {
+  test('valid themePath 2 with components', async () => {
     const fixtures = path.join(__dirname, '__fixtures__');
     const themePath = path.join(fixtures, 'theme-2');
-    const alias = themeAlias(themePath, true);
+    const alias = await themeAlias(themePath, true);
     // Testing entries, because order matters!
     expect(Object.entries(alias)).toEqual(
       Object.entries({
@@ -83,10 +83,10 @@ describe('themeAlias', () => {
     expect(alias).not.toEqual({});
   });
 
-  test('valid themePath 2 with components without original', () => {
+  test('valid themePath 2 with components without original', async () => {
     const fixtures = path.join(__dirname, '__fixtures__');
     const themePath = path.join(fixtures, 'theme-2');
-    const alias = themeAlias(themePath, false);
+    const alias = await themeAlias(themePath, false);
     // Testing entries, because order matters!
     expect(Object.entries(alias)).toEqual(
       Object.entries({
@@ -107,26 +107,26 @@ describe('themeAlias', () => {
     expect(alias).not.toEqual({});
   });
 
-  test('valid themePath with no components', () => {
+  test('valid themePath with no components', async () => {
     const fixtures = path.join(__dirname, '__fixtures__');
     const themePath = path.join(fixtures, 'empty-theme');
-    fs.ensureDirSync(themePath);
-    const alias = themeAlias(themePath, true);
+    await fs.ensureDir(themePath);
+    const alias = await themeAlias(themePath, true);
     expect(alias).toEqual({});
   });
 
-  test('valid themePath with no components without original', () => {
+  test('valid themePath with no components without original', async () => {
     const fixtures = path.join(__dirname, '__fixtures__');
     const themePath = path.join(fixtures, 'empty-theme');
-    fs.ensureDirSync(themePath);
-    const alias = themeAlias(themePath, false);
+    await fs.ensureDir(themePath);
+    const alias = await themeAlias(themePath, false);
     expect(alias).toEqual({});
   });
 
-  test('invalid themePath that does not exist', () => {
+  test('invalid themePath that does not exist', async () => {
     const fixtures = path.join(__dirname, '__fixtures__');
     const themePath = path.join(fixtures, '__noExist__');
-    const alias = themeAlias(themePath, true);
+    const alias = await themeAlias(themePath, true);
     expect(alias).toEqual({});
   });
 });
diff --git a/packages/docusaurus/src/server/themes/__tests__/index.test.ts b/packages/docusaurus/src/server/themes/__tests__/index.test.ts
index 157ec169d3..9c42f76074 100644
--- a/packages/docusaurus/src/server/themes/__tests__/index.test.ts
+++ b/packages/docusaurus/src/server/themes/__tests__/index.test.ts
@@ -9,12 +9,12 @@ import path from 'path';
 import {loadThemeAliases} from '../index';
 
 describe('loadThemeAliases', () => {
-  test('next alias can override the previous alias', () => {
+  test('next alias can override the previous alias', async () => {
     const fixtures = path.join(__dirname, '__fixtures__');
     const theme1Path = path.join(fixtures, 'theme-1');
     const theme2Path = path.join(fixtures, 'theme-2');
 
-    const alias = loadThemeAliases([theme1Path, theme2Path], []);
+    const alias = await loadThemeAliases([theme1Path, theme2Path], []);
 
     // Testing entries, because order matters!
     expect(Object.entries(alias)).toEqual(
diff --git a/packages/docusaurus/src/server/themes/alias.ts b/packages/docusaurus/src/server/themes/alias.ts
index 3ced5b26be..f6f3478c94 100644
--- a/packages/docusaurus/src/server/themes/alias.ts
+++ b/packages/docusaurus/src/server/themes/alias.ts
@@ -25,16 +25,15 @@ export function sortAliases(aliases: ThemeAliases): ThemeAliases {
   return Object.fromEntries(entries);
 }
 
-// TODO make async
-export default function themeAlias(
+export default async function themeAlias(
   themePath: string,
   addOriginalAlias: boolean,
-): ThemeAliases {
-  if (!fs.pathExistsSync(themePath)) {
+): Promise<ThemeAliases> {
+  if (!(await fs.pathExists(themePath))) {
     return {};
   }
 
-  const themeComponentFiles = Globby.sync(['**/*.{js,jsx,ts,tsx}'], {
+  const themeComponentFiles = await Globby(['**/*.{js,jsx,ts,tsx}'], {
     cwd: themePath,
   });
 
diff --git a/packages/docusaurus/src/server/themes/index.ts b/packages/docusaurus/src/server/themes/index.ts
index cb973e0e2a..9c4940aa8b 100644
--- a/packages/docusaurus/src/server/themes/index.ts
+++ b/packages/docusaurus/src/server/themes/index.ts
@@ -12,14 +12,14 @@ import themeAlias, {sortAliases} from './alias';
 
 const ThemeFallbackDir = path.resolve(__dirname, '../../client/theme-fallback');
 
-export function loadThemeAliases(
+export async function loadThemeAliases(
   themePaths: string[],
   userThemePaths: string[],
-): ThemeAliases {
+): Promise<ThemeAliases> {
   const aliases: ThemeAliases = {};
 
-  themePaths.forEach((themePath) => {
-    const themeAliases = themeAlias(themePath, true);
+  for (const themePath of themePaths) {
+    const themeAliases = await themeAlias(themePath, true);
     Object.keys(themeAliases).forEach((aliasKey) => {
       // If this alias shadows a previous one, use @theme-init to preserve the
       // initial one. @theme-init is only applied once: to the initial theme
@@ -33,12 +33,12 @@ export function loadThemeAliases(
       }
       aliases[aliasKey] = themeAliases[aliasKey];
     });
-  });
+  }
 
-  userThemePaths.forEach((themePath) => {
-    const userThemeAliases = themeAlias(themePath, false);
+  for (const themePath of userThemePaths) {
+    const userThemeAliases = await themeAlias(themePath, false);
     Object.assign(aliases, userThemeAliases);
-  });
+  }
 
   return sortAliases(aliases);
 }
@@ -49,7 +49,7 @@ export function loadPluginsThemeAliases({
 }: {
   siteDir: string;
   plugins: LoadedPlugin[];
-}): ThemeAliases {
+}): Promise<ThemeAliases> {
   const pluginThemes: string[] = plugins
     .map((plugin) => (plugin.getThemePath ? plugin.getThemePath() : undefined))
     .filter((x): x is string => Boolean(x));
diff --git a/packages/docusaurus/src/server/utils.ts b/packages/docusaurus/src/server/utils.ts
index 37a3f160d6..e4e22df7d9 100644
--- a/packages/docusaurus/src/server/utils.ts
+++ b/packages/docusaurus/src/server/utils.ts
@@ -6,7 +6,7 @@
  */
 
 import type {RouteConfig} from '@docusaurus/types';
-import nodePath from 'path';
+import path from 'path';
 import {posixPath, Globby} from '@docusaurus/utils';
 
 // Recursively get the final routes (routes with no subroutes)
@@ -26,7 +26,7 @@ export async function safeGlobby(
   // Required for Windows support, as paths using \ should not be used by globby
   // (also using the windows hard drive prefix like c: is not a good idea)
   const globPaths = patterns.map((dirPath) =>
-    posixPath(nodePath.relative(process.cwd(), dirPath)),
+    posixPath(path.relative(process.cwd(), dirPath)),
   );
 
   return Globby(globPaths, options);
diff --git a/packages/docusaurus/src/server/versions/__tests__/index.test.ts b/packages/docusaurus/src/server/versions/__tests__/index.test.ts
index e7ba75d5f6..377cb6f2ab 100644
--- a/packages/docusaurus/src/server/versions/__tests__/index.test.ts
+++ b/packages/docusaurus/src/server/versions/__tests__/index.test.ts
@@ -9,27 +9,27 @@ import {getPluginVersion} from '..';
 import path from 'path';
 
 describe('getPluginVersion', () => {
-  it('Can detect external packages plugins versions of correctly.', () => {
-    expect(
+  it('Can detect external packages plugins versions of correctly.', async () => {
+    await expect(
       getPluginVersion(
         path.join(__dirname, '..', '__fixtures__', 'dummy-plugin.js'),
         // Make the plugin appear external.
         path.join(__dirname, '..', '..', '..', '..', '..', '..', 'website'),
       ),
-    ).toEqual({type: 'package', version: 'random-version'});
+    ).resolves.toEqual({type: 'package', version: 'random-version'});
   });
 
-  it('Can detect project plugins versions correctly.', () => {
-    expect(
+  it('Can detect project plugins versions correctly.', async () => {
+    await expect(
       getPluginVersion(
         path.join(__dirname, '..', '__fixtures__', 'dummy-plugin.js'),
         // Make the plugin appear project local.
         path.join(__dirname, '..', '__fixtures__'),
       ),
-    ).toEqual({type: 'project'});
+    ).resolves.toEqual({type: 'project'});
   });
 
-  it('Can detect local packages versions correctly.', () => {
-    expect(getPluginVersion('/', '/')).toEqual({type: 'local'});
+  it('Can detect local packages versions correctly.', async () => {
+    await expect(getPluginVersion('/', '/')).resolves.toEqual({type: 'local'});
   });
 });
diff --git a/packages/docusaurus/src/server/versions/index.ts b/packages/docusaurus/src/server/versions/index.ts
index 3df9f84923..32c374463a 100644
--- a/packages/docusaurus/src/server/versions/index.ts
+++ b/packages/docusaurus/src/server/versions/index.ts
@@ -6,13 +6,13 @@
  */
 
 import type {DocusaurusPluginVersionInformation} from '@docusaurus/types';
-import {existsSync, lstatSync} from 'fs-extra';
-import {dirname, join} from 'path';
+import fs from 'fs-extra';
+import path from 'path';
 
-export function getPackageJsonVersion(
+export async function getPackageJsonVersion(
   packageJsonPath: string,
-): string | undefined {
-  if (existsSync(packageJsonPath)) {
+): Promise<string | undefined> {
+  if (await fs.pathExists(packageJsonPath)) {
     // eslint-disable-next-line @typescript-eslint/no-var-requires, import/no-dynamic-require, global-require
     const {version} = require(packageJsonPath);
     return typeof version === 'string' ? version : undefined;
@@ -20,10 +20,10 @@ export function getPackageJsonVersion(
   return undefined;
 }
 
-export function getPackageJsonName(
+export async function getPackageJsonName(
   packageJsonPath: string,
-): string | undefined {
-  if (existsSync(packageJsonPath)) {
+): Promise<string | undefined> {
+  if (await fs.pathExists(packageJsonPath)) {
     // eslint-disable-next-line @typescript-eslint/no-var-requires, import/no-dynamic-require, global-require
     const {name} = require(packageJsonPath);
     return typeof name === 'string' ? name : undefined;
@@ -31,17 +31,20 @@ export function getPackageJsonName(
   return undefined;
 }
 
-export function getPluginVersion(
+export async function getPluginVersion(
   pluginPath: string,
   siteDir: string,
-): DocusaurusPluginVersionInformation {
-  let potentialPluginPackageJsonDirectory = dirname(pluginPath);
+): Promise<DocusaurusPluginVersionInformation> {
+  let potentialPluginPackageJsonDirectory = path.dirname(pluginPath);
   while (potentialPluginPackageJsonDirectory !== '/') {
-    const packageJsonPath = join(
+    const packageJsonPath = path.join(
       potentialPluginPackageJsonDirectory,
       'package.json',
     );
-    if (existsSync(packageJsonPath) && lstatSync(packageJsonPath).isFile()) {
+    if (
+      (await fs.pathExists(packageJsonPath)) &&
+      (await fs.lstat(packageJsonPath)).isFile()
+    ) {
       if (potentialPluginPackageJsonDirectory === siteDir) {
         // If the plugin belongs to the same docusaurus project, we classify it
         // as local plugin.
@@ -49,11 +52,11 @@ export function getPluginVersion(
       }
       return {
         type: 'package',
-        name: getPackageJsonName(packageJsonPath),
-        version: getPackageJsonVersion(packageJsonPath),
+        name: await getPackageJsonName(packageJsonPath),
+        version: await getPackageJsonVersion(packageJsonPath),
       };
     }
-    potentialPluginPackageJsonDirectory = dirname(
+    potentialPluginPackageJsonDirectory = path.dirname(
       potentialPluginPackageJsonDirectory,
     );
   }
diff --git a/packages/docusaurus/src/webpack/__tests__/base.test.ts b/packages/docusaurus/src/webpack/__tests__/base.test.ts
index 14c41df56e..8e2ccb9703 100644
--- a/packages/docusaurus/src/webpack/__tests__/base.test.ts
+++ b/packages/docusaurus/src/webpack/__tests__/base.test.ts
@@ -68,10 +68,10 @@ describe('babel transpilation exclude logic', () => {
 });
 
 describe('getDocusaurusAliases()', () => {
-  test('return appropriate webpack aliases', () => {
+  test('return appropriate webpack aliases', async () => {
     // using relative paths makes tests work everywhere
     const relativeDocusaurusAliases = _.mapValues(
-      getDocusaurusAliases(),
+      await getDocusaurusAliases(),
       (aliasValue) => posixPath(path.relative(__dirname, aliasValue)),
     );
     expect(relativeDocusaurusAliases).toMatchSnapshot();
@@ -120,10 +120,10 @@ describe('base webpack config', () => {
     jest.restoreAllMocks();
   });
 
-  test('should create webpack aliases', () => {
+  test('should create webpack aliases', async () => {
     // @ts-expect-error: Docusaurus webpack alias is always an object
     const aliases: ThemeAliases =
-      createBaseConfig(props, true).resolve?.alias ?? {};
+      (await createBaseConfig(props, true)).resolve?.alias ?? {};
     // Make aliases relative so that test work on all computers
     const relativeAliases = _.mapValues(aliases, (a) =>
       posixPath(path.relative(props.siteDir, a)),
@@ -131,14 +131,14 @@ describe('base webpack config', () => {
     expect(relativeAliases).toMatchSnapshot();
   });
 
-  test('should use svg rule', () => {
+  test('should use svg rule', async () => {
     const fileLoaderUtils = utils.getFileLoaderUtils();
     const mockSvg = jest.spyOn(fileLoaderUtils.rules, 'svg');
     jest
       .spyOn(utils, 'getFileLoaderUtils')
       .mockImplementation(() => fileLoaderUtils);
 
-    createBaseConfig(props, false, false);
+    await createBaseConfig(props, false, false);
     expect(mockSvg).toBeCalled();
   });
 });
diff --git a/packages/docusaurus/src/webpack/__tests__/client.test.ts b/packages/docusaurus/src/webpack/__tests__/client.test.ts
index 5e93c1e739..b9f40387b4 100644
--- a/packages/docusaurus/src/webpack/__tests__/client.test.ts
+++ b/packages/docusaurus/src/webpack/__tests__/client.test.ts
@@ -14,7 +14,7 @@ describe('webpack dev config', () => {
   test('simple', async () => {
     console.log = jest.fn();
     const props = await loadSetup('simple');
-    const config = createClientConfig(props);
+    const config = await createClientConfig(props);
     const errors = validate(config);
     expect(errors).toBeUndefined();
   });
@@ -22,7 +22,7 @@ describe('webpack dev config', () => {
   test('custom', async () => {
     console.log = jest.fn();
     const props = await loadSetup('custom');
-    const config = createClientConfig(props);
+    const config = await createClientConfig(props);
     const errors = validate(config);
     expect(errors).toBeUndefined();
   });
diff --git a/packages/docusaurus/src/webpack/__tests__/server.test.ts b/packages/docusaurus/src/webpack/__tests__/server.test.ts
index 75f95fd56a..be8f72e08e 100644
--- a/packages/docusaurus/src/webpack/__tests__/server.test.ts
+++ b/packages/docusaurus/src/webpack/__tests__/server.test.ts
@@ -14,7 +14,7 @@ describe('webpack production config', () => {
   test('simple', async () => {
     console.log = jest.fn();
     const props = await loadSetup('simple');
-    const config = createServerConfig({props});
+    const config = await createServerConfig({props});
     const errors = validate(config);
     expect(errors).toBeUndefined();
   });
@@ -22,7 +22,7 @@ describe('webpack production config', () => {
   test('custom', async () => {
     console.log = jest.fn();
     const props = await loadSetup('custom');
-    const config = createServerConfig({props});
+    const config = await createServerConfig({props});
     const errors = validate(config);
     expect(errors).toBeUndefined();
   });
diff --git a/packages/docusaurus/src/webpack/base.ts b/packages/docusaurus/src/webpack/base.ts
index 1a2b57f1d8..7f4f963139 100644
--- a/packages/docusaurus/src/webpack/base.ts
+++ b/packages/docusaurus/src/webpack/base.ts
@@ -44,13 +44,13 @@ export function excludeJS(modulePath: string): boolean {
   );
 }
 
-export function getDocusaurusAliases(): Record<string, string> {
+export async function getDocusaurusAliases(): Promise<Record<string, string>> {
   const dirPath = path.resolve(__dirname, '../client/exports');
   const extensions = ['.js', '.ts', '.tsx'];
 
   const aliases: Record<string, string> = {};
 
-  fs.readdirSync(dirPath)
+  (await fs.readdir(dirPath))
     .filter((fileName) => extensions.includes(path.extname(fileName)))
     .forEach((fileName) => {
       const fileNameWithoutExtension = path.basename(
@@ -64,11 +64,11 @@ export function getDocusaurusAliases(): Record<string, string> {
   return aliases;
 }
 
-export function createBaseConfig(
+export async function createBaseConfig(
   props: Props,
   isServer: boolean,
   minify: boolean = true,
-): Configuration {
+): Promise<Configuration> {
   const {
     outDir,
     siteDir,
@@ -90,7 +90,7 @@ export function createBaseConfig(
   const name = isServer ? 'server' : 'client';
   const mode = isProd ? 'production' : 'development';
 
-  const themeAliases = loadPluginsThemeAliases({siteDir, plugins});
+  const themeAliases = await loadPluginsThemeAliases({siteDir, plugins});
 
   return {
     mode,
@@ -158,7 +158,7 @@ export function createBaseConfig(
         // Note: a @docusaurus alias would also catch @docusaurus/theme-common,
         // so we use fine-grained aliases instead
         // '@docusaurus': path.resolve(__dirname, '../client/exports'),
-        ...getDocusaurusAliases(),
+        ...(await getDocusaurusAliases()),
         ...themeAliases,
       },
       // This allows you to set a fallback for where Webpack should look for
@@ -169,7 +169,7 @@ export function createBaseConfig(
       modules: [
         path.resolve(__dirname, '..', '..', 'node_modules'),
         'node_modules',
-        path.resolve(fs.realpathSync(process.cwd()), 'node_modules'),
+        path.resolve(await fs.realpath(process.cwd()), 'node_modules'),
       ],
     },
     resolveLoader: {
@@ -225,7 +225,7 @@ export function createBaseConfig(
           use: [
             getCustomizableJSLoader(siteConfig.webpack?.jsLoader)({
               isServer,
-              babelOptions: getCustomBabelConfigFilePath(siteDir),
+              babelOptions: await getCustomBabelConfigFilePath(siteDir),
             }),
           ],
         },
diff --git a/packages/docusaurus/src/webpack/client.ts b/packages/docusaurus/src/webpack/client.ts
index 0942e0c078..ffe0a704eb 100644
--- a/packages/docusaurus/src/webpack/client.ts
+++ b/packages/docusaurus/src/webpack/client.ts
@@ -15,12 +15,12 @@ import {createBaseConfig} from './base';
 import ChunkAssetPlugin from './plugins/ChunkAssetPlugin';
 import LogPlugin from './plugins/LogPlugin';
 
-export default function createClientConfig(
+export default async function createClientConfig(
   props: Props,
   minify: boolean = true,
-): Configuration {
+): Promise<Configuration> {
   const isBuilding = process.argv[2] === 'build';
-  const config = createBaseConfig(props, false, minify);
+  const config = await createBaseConfig(props, false, minify);
 
   const clientConfig = merge(config, {
     // useless, disabled on purpose (errors on existing sites with no
diff --git a/packages/docusaurus/src/webpack/server.ts b/packages/docusaurus/src/webpack/server.ts
index 85aa0a6722..cc3578d058 100644
--- a/packages/docusaurus/src/webpack/server.ts
+++ b/packages/docusaurus/src/webpack/server.ts
@@ -18,13 +18,13 @@ import {NODE_MAJOR_VERSION, NODE_MINOR_VERSION} from '@docusaurus/utils';
 // Forked for Docusaurus: https://github.com/slorber/static-site-generator-webpack-plugin
 import StaticSiteGeneratorPlugin from '@slorber/static-site-generator-webpack-plugin';
 
-export default function createServerConfig({
+export default async function createServerConfig({
   props,
   onLinksCollected = () => {},
 }: {
   props: Props;
   onLinksCollected?: (staticPagePath: string, links: string[]) => void;
-}): Configuration {
+}): Promise<Configuration> {
   const {
     baseUrl,
     routesPaths,
@@ -35,7 +35,7 @@ export default function createServerConfig({
     ssrTemplate,
     siteConfig: {noIndex, trailingSlash},
   } = props;
-  const config = createBaseConfig(props, true);
+  const config = await createBaseConfig(props, true);
 
   const routesLocation: Record<string, string> = {};
   // Array of paths to be rendered. Relative to output directory
diff --git a/packages/docusaurus/src/webpack/utils.ts b/packages/docusaurus/src/webpack/utils.ts
index 6d7e31b6fa..5c17c05522 100644
--- a/packages/docusaurus/src/webpack/utils.ts
+++ b/packages/docusaurus/src/webpack/utils.ts
@@ -101,14 +101,14 @@ export function getStyleLoaders(
   ];
 }
 
-export function getCustomBabelConfigFilePath(
+export async function getCustomBabelConfigFilePath(
   siteDir: string,
-): string | undefined {
+): Promise<string | undefined> {
   const customBabelConfigurationPath = path.join(
     siteDir,
     BABEL_CONFIG_FILE_NAME,
   );
-  return fs.existsSync(customBabelConfigurationPath)
+  return (await fs.pathExists(customBabelConfigurationPath))
     ? customBabelConfigurationPath
     : undefined;
 }
@@ -333,19 +333,21 @@ ${err}`,
 }
 
 // Read file and throw an error if it doesn't exist
-function readEnvFile(file: string, type: string) {
-  if (!fs.existsSync(file)) {
+async function readEnvFile(file: string, type: string) {
+  if (!(await fs.pathExists(file))) {
     throw new Error(
       `You specified ${type} in your env, but the file "${file}" can't be found.`,
     );
   }
-  return fs.readFileSync(file);
+  return fs.readFile(file);
 }
 
-const appDirectory = fs.realpathSync(process.cwd());
 // Get the https config
 // Return cert files if provided in env, otherwise just true or false
-export function getHttpsConfig(): boolean | {cert: Buffer; key: Buffer} {
+export async function getHttpsConfig(): Promise<
+  boolean | {cert: Buffer; key: Buffer}
+> {
+  const appDirectory = await fs.realpath(process.cwd());
   const {SSL_CRT_FILE, SSL_KEY_FILE, HTTPS} = process.env;
   const isHttps = HTTPS === 'true';
 
@@ -353,8 +355,8 @@ export function getHttpsConfig(): boolean | {cert: Buffer; key: Buffer} {
     const crtFile = path.resolve(appDirectory, SSL_CRT_FILE);
     const keyFile = path.resolve(appDirectory, SSL_KEY_FILE);
     const config = {
-      cert: readEnvFile(crtFile, 'SSL_CRT_FILE'),
-      key: readEnvFile(keyFile, 'SSL_KEY_FILE'),
+      cert: await readEnvFile(crtFile, 'SSL_CRT_FILE'),
+      key: await readEnvFile(keyFile, 'SSL_KEY_FILE'),
     };
 
     validateKeyAndCerts({...config, keyFile, crtFile});
diff --git a/website/_dogfooding/dogfooding.config.js b/website/_dogfooding/dogfooding.config.js
index 3d087da411..968d90e385 100644
--- a/website/_dogfooding/dogfooding.config.js
+++ b/website/_dogfooding/dogfooding.config.js
@@ -19,6 +19,7 @@ const dogfoodingPluginInstances = [
 
       // Using a symlinked folder as source, test for use-case https://github.com/facebook/docusaurus/issues/3272
       // The target folder uses a _ prefix to test against an edge case regarding MDX partials: https://github.com/facebook/docusaurus/discussions/5181#discussioncomment-1018079
+      // eslint-disable-next-line no-restricted-properties
       path: fs.realpathSync('_dogfooding/docs-tests-symlink'),
       showLastUpdateTime: true,
       sidebarItemsGenerator(args) {
diff --git a/website/src/data/__tests__/user.test.ts b/website/src/data/__tests__/user.test.ts
index f6e80becea..bb3b83d91f 100644
--- a/website/src/data/__tests__/user.test.ts
+++ b/website/src/data/__tests__/user.test.ts
@@ -49,7 +49,7 @@ expect.extend({
 
 describe('users', () => {
   sortedUsers.forEach((user) => {
-    test(user.title, () => {
+    test(user.title, async () => {
       Joi.attempt(
         user,
         Joi.object<User>({
@@ -86,6 +86,7 @@ describe('users', () => {
   });
 
   const imageDir = path.join(__dirname, '../showcase');
+  // eslint-disable-next-line no-restricted-properties
   const files = fs
     .readdirSync(imageDir)
     .filter((file) => ['.png', 'jpg', '.jpeg'].includes(path.extname(file)));