diff --git a/packages/docusaurus-migrate/src/index.ts b/packages/docusaurus-migrate/src/index.ts
index 4f2a5ceb7e..c3064d9b2e 100644
--- a/packages/docusaurus-migrate/src/index.ts
+++ b/packages/docusaurus-migrate/src/index.ts
@@ -618,7 +618,6 @@ function migrateVersionedSidebar(
       const newSidebar = Object.entries(sidebar.entries).reduce(
         (acc: SidebarEntries, val) => {
           const key = `version-${sidebar.version}/${val[0]}`;
-          // eslint-disable-next-line prefer-destructuring
           acc[key] = Object.entries(val[1]).map((value) => {
             return {
               type: 'category',
diff --git a/packages/docusaurus-module-type-aliases/src/index.d.ts b/packages/docusaurus-module-type-aliases/src/index.d.ts
index d195eafd08..14b65e17c5 100644
--- a/packages/docusaurus-module-type-aliases/src/index.d.ts
+++ b/packages/docusaurus-module-type-aliases/src/index.d.ts
@@ -11,12 +11,16 @@ declare module '@generated/client-modules' {
 }
 
 declare module '@generated/docusaurus.config' {
-  const config: any;
+  import type {DocusaurusConfig} from '@docusaurus/types';
+
+  const config: DocusaurusConfig;
   export default config;
 }
 
 declare module '@generated/site-metadata' {
-  const siteMetadata: any;
+  import type {DocusaurusSiteMetadata} from '@docusaurus/types';
+
+  const siteMetadata: DocusaurusSiteMetadata;
   export default siteMetadata;
 }
 
@@ -28,9 +32,11 @@ declare module '@generated/registry' {
 }
 
 declare module '@generated/routes' {
+  import type {RouteConfig} from 'react-router-config';
+
   type Route = {
     readonly path: string;
-    readonly component: any;
+    readonly component: RouteConfig['component'];
     readonly exact?: boolean;
   };
   const routes: Route[];
@@ -79,16 +85,11 @@ declare module '@docusaurus/Head' {
 }
 
 declare module '@docusaurus/Link' {
-  import type {ReactNode} from 'react';
-
-  type RRLinkProps = Partial<import('react-router-dom').LinkProps>;
-  export type LinkProps = RRLinkProps & {
+  type NavLinkProps = Partial<import('react-router-dom').NavLinkProps>;
+  export type LinkProps = NavLinkProps & {
     readonly isNavLink?: boolean;
     readonly to?: string;
     readonly href?: string;
-    readonly activeClassName?: string;
-    readonly children?: ReactNode;
-    readonly isActive?: (match: any, location: any) => boolean;
     readonly autoAddBaseUrl?: boolean;
 
     // escape hatch in case broken links check is annoying for a specific link
@@ -173,7 +174,9 @@ declare module '@docusaurus/history' {
 }
 
 declare module '@docusaurus/useDocusaurusContext' {
-  export default function (): any;
+  import type {DocusaurusContext} from '@docusaurus/types';
+
+  export default function useDocusaurusContext(): DocusaurusContext;
 }
 
 declare module '@docusaurus/useBaseUrl' {
diff --git a/packages/docusaurus-plugin-content-blog/index.d.ts b/packages/docusaurus-plugin-content-blog/index.d.ts
index 48cd3c38da..e8d2d88889 100644
--- a/packages/docusaurus-plugin-content-blog/index.d.ts
+++ b/packages/docusaurus-plugin-content-blog/index.d.ts
@@ -5,9 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-/* eslint-disable import/no-duplicates */
-/* eslint-disable camelcase */
-
 declare module '@theme/BlogSidebar' {
   export type BlogSidebarItem = {title: string; permalink: string};
   export type BlogSidebar = {
@@ -28,6 +25,7 @@ declare module '@theme/BlogPostPage' {
   import type {BlogSidebar} from '@theme/BlogSidebar';
 
   export type FrontMatter = {
+    /* eslint-disable camelcase */
     readonly title: string;
     readonly author?: string;
     readonly image?: string;
@@ -40,12 +38,15 @@ declare module '@theme/BlogPostPage' {
     readonly author_image_url?: string;
     readonly authorImageURL?: string;
     readonly hide_table_of_contents?: boolean;
+    /* eslint-enable camelcase */
   };
 
   export type FrontMatterAssets = {
+    /* eslint-disable camelcase */
     readonly image?: string;
     readonly author_image_url?: string;
     readonly authorImageURL?: string;
+    /* eslint-enable camelcase */
   };
 
   export type Metadata = {
diff --git a/packages/docusaurus-plugin-content-blog/src/blogFrontMatter.ts b/packages/docusaurus-plugin-content-blog/src/blogFrontMatter.ts
index a9ad7c16d7..2d8490a5be 100644
--- a/packages/docusaurus-plugin-content-blog/src/blogFrontMatter.ts
+++ b/packages/docusaurus-plugin-content-blog/src/blogFrontMatter.ts
@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-/* eslint-disable camelcase */
-
 import {
   JoiFrontMatter as Joi, // Custom instance for frontmatter
   URISchema,
@@ -15,6 +13,7 @@ import {
 import {Tag} from './types';
 
 export type BlogPostFrontMatter = {
+  /* eslint-disable camelcase */
   id?: string;
   title?: string;
   description?: string;
@@ -36,6 +35,7 @@ export type BlogPostFrontMatter = {
   authorTitle?: string;
   authorURL?: string;
   authorImageURL?: string;
+  /* eslint-enable camelcase */
 };
 
 // NOTE: we don't add any default value on purpose here
diff --git a/packages/docusaurus-plugin-content-docs/src/cli.ts b/packages/docusaurus-plugin-content-docs/src/cli.ts
index 41de537f1c..cb6e01efb8 100644
--- a/packages/docusaurus-plugin-content-docs/src/cli.ts
+++ b/packages/docusaurus-plugin-content-docs/src/cli.ts
@@ -85,7 +85,6 @@ function createVersionedSidebarFile({
 }
 
 // Tests depend on non-default export for mocking.
-// eslint-disable-next-line import/prefer-default-export
 export function cliDocsVersionCommand(
   version: string | null | undefined,
   siteDir: string,
diff --git a/packages/docusaurus-plugin-content-docs/src/docFrontMatter.ts b/packages/docusaurus-plugin-content-docs/src/docFrontMatter.ts
index 70e1d8ac33..70b2049e77 100644
--- a/packages/docusaurus-plugin-content-docs/src/docFrontMatter.ts
+++ b/packages/docusaurus-plugin-content-docs/src/docFrontMatter.ts
@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-/* eslint-disable camelcase */
-
 import {
   JoiFrontMatter as Joi, // Custom instance for frontmatter
   URISchema,
diff --git a/packages/docusaurus-plugin-content-docs/src/docs.ts b/packages/docusaurus-plugin-content-docs/src/docs.ts
index 00f830c0e7..29f0a1e1e0 100644
--- a/packages/docusaurus-plugin-content-docs/src/docs.ts
+++ b/packages/docusaurus-plugin-content-docs/src/docs.ts
@@ -130,9 +130,8 @@ function doProcessDocMetadata({
     custom_edit_url: customEditURL,
 
     // Strip number prefixes by default (01-MyFolder/01-MyDoc.md => MyFolder/MyDoc) by default,
-    // but allow to disable this behavior with frontmatterr
-    // eslint-disable-next-line camelcase
-    parse_number_prefixes = true,
+    // but allow to disable this behavior with frontmatter
+    parse_number_prefixes: parseNumberPrefixes = true,
   } = frontMatter;
 
   // ex: api/plugins/myDoc -> myDoc
@@ -146,8 +145,7 @@ function doProcessDocMetadata({
   // ex: myDoc -> .
   const sourceDirName = path.dirname(source);
 
-  // eslint-disable-next-line camelcase
-  const {filename: unprefixedFileName, numberPrefix} = parse_number_prefixes
+  const {filename: unprefixedFileName, numberPrefix} = parseNumberPrefixes
     ? options.numberPrefixParser(sourceFileNameWithoutExtension)
     : {filename: sourceFileNameWithoutExtension, numberPrefix: undefined};
 
@@ -175,8 +173,7 @@ function doProcessDocMetadata({
       return undefined;
     }
     // Eventually remove the number prefixes from intermediate directories
-    // eslint-disable-next-line camelcase
-    return parse_number_prefixes
+    return parseNumberPrefixes
       ? stripPathNumberPrefixes(sourceDirName, options.numberPrefixParser)
       : sourceDirName;
   }
@@ -203,7 +200,7 @@ function doProcessDocMetadata({
         baseID,
         dirName: sourceDirName,
         frontmatterSlug: frontMatter.slug,
-        stripDirNumberPrefixes: parse_number_prefixes,
+        stripDirNumberPrefixes: parseNumberPrefixes,
         numberPrefixParser: options.numberPrefixParser,
       });
 
diff --git a/packages/docusaurus-plugin-content-docs/src/plugin-content-docs.d.ts b/packages/docusaurus-plugin-content-docs/src/plugin-content-docs.d.ts
index e371da2217..cc4b1314f6 100644
--- a/packages/docusaurus-plugin-content-docs/src/plugin-content-docs.d.ts
+++ b/packages/docusaurus-plugin-content-docs/src/plugin-content-docs.d.ts
@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-/* eslint-disable camelcase */
-
 declare module '@docusaurus/plugin-content-docs-types' {
   type VersionBanner = import('./types').VersionBanner;
   type GlobalDataVersion = import('./types').GlobalVersion;
@@ -64,8 +62,10 @@ declare module '@theme/DocItem' {
     readonly title: string;
     readonly image?: string;
     readonly keywords?: readonly string[];
+    /* eslint-disable camelcase */
     readonly hide_title?: boolean;
     readonly hide_table_of_contents?: boolean;
+    /* eslint-enable camelcase */
   };
 
   export type Metadata = {
diff --git a/packages/docusaurus-theme-bootstrap/src/theme/DebugLayout/index.tsx b/packages/docusaurus-theme-bootstrap/src/theme/DebugLayout/index.tsx
index 78b3736b17..7505ee2c27 100644
--- a/packages/docusaurus-theme-bootstrap/src/theme/DebugLayout/index.tsx
+++ b/packages/docusaurus-theme-bootstrap/src/theme/DebugLayout/index.tsx
@@ -9,7 +9,7 @@ import React from 'react';
 
 import Head from '@docusaurus/Head';
 import isInternalUrl from '@docusaurus/isInternalUrl';
-import {useTitleFormatter} from '@docusaurus/theme-common';
+import {useTitleFormatter, useThemeConfig} from '@docusaurus/theme-common';
 import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
 import useBaseUrl from '@docusaurus/useBaseUrl';
 
@@ -18,12 +18,9 @@ import Footer from '@theme/Footer';
 import type {Props} from '@theme/Layout';
 
 function Layout(props: Props): JSX.Element {
-  const {siteConfig = {}} = useDocusaurusContext();
-  const {
-    favicon,
-    themeConfig: {image: defaultImage, metadatas},
-    url: siteUrl,
-  } = siteConfig;
+  const {siteConfig} = useDocusaurusContext();
+  const {favicon, url: siteUrl} = siteConfig;
+  const {image: defaultImage, metadatas} = useThemeConfig();
   const {
     children,
     title,
diff --git a/packages/docusaurus-theme-bootstrap/src/theme/DocItem/index.tsx b/packages/docusaurus-theme-bootstrap/src/theme/DocItem/index.tsx
index 928e1527e5..cd78befe9a 100644
--- a/packages/docusaurus-theme-bootstrap/src/theme/DocItem/index.tsx
+++ b/packages/docusaurus-theme-bootstrap/src/theme/DocItem/index.tsx
@@ -15,7 +15,7 @@ import useBaseUrl from '@docusaurus/useBaseUrl';
 import {Props} from '@theme/DocItem';
 
 function DocItem(props: Props): JSX.Element {
-  const {siteConfig = {}} = useDocusaurusContext();
+  const {siteConfig = {url: ''}} = useDocusaurusContext();
   const {url: siteUrl} = siteConfig;
   const {content: DocContent} = props;
   const {metadata} = DocContent;
diff --git a/packages/docusaurus-theme-bootstrap/src/theme/Footer/index.tsx b/packages/docusaurus-theme-bootstrap/src/theme/Footer/index.tsx
index 196df050aa..7ca080e5b9 100644
--- a/packages/docusaurus-theme-bootstrap/src/theme/Footer/index.tsx
+++ b/packages/docusaurus-theme-bootstrap/src/theme/Footer/index.tsx
@@ -6,11 +6,20 @@
  */
 
 import React from 'react';
-import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
 import Link from '@docusaurus/Link';
 import useBaseUrl from '@docusaurus/useBaseUrl';
+import {useThemeConfig} from '@docusaurus/theme-common';
 
-function FooterLink({to, href, label, ...props}) {
+function FooterLink({
+  to,
+  href,
+  label,
+  ...props
+}: {
+  to?: string;
+  href?: string;
+  label?: string;
+}) {
   const toUrl = useBaseUrl(to);
 
   return (
@@ -31,12 +40,9 @@ function FooterLink({to, href, label, ...props}) {
 }
 
 function Footer(): JSX.Element {
-  const context = useDocusaurusContext();
-  const {siteConfig = {}} = context;
-  const {themeConfig = {}} = siteConfig;
-  const {footer} = themeConfig;
+  const {footer} = useThemeConfig();
 
-  const {links} = footer || {};
+  const {links = []} = footer || {};
 
   return (
     <footer className="container-fluid p-0 align-self-end">
diff --git a/packages/docusaurus-theme-bootstrap/src/theme/Layout/index.tsx b/packages/docusaurus-theme-bootstrap/src/theme/Layout/index.tsx
index 1cc6c68632..5182d16c04 100644
--- a/packages/docusaurus-theme-bootstrap/src/theme/Layout/index.tsx
+++ b/packages/docusaurus-theme-bootstrap/src/theme/Layout/index.tsx
@@ -10,6 +10,7 @@ import React from 'react';
 import Head from '@docusaurus/Head';
 import isInternalUrl from '@docusaurus/isInternalUrl';
 import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
+import {useThemeConfig} from '@docusaurus/theme-common';
 import useBaseUrl from '@docusaurus/useBaseUrl';
 
 import Navbar from '@theme/Navbar';
@@ -18,12 +19,7 @@ import type {Props} from '@theme/Layout';
 
 function Layout(props: Props): JSX.Element {
   const {siteConfig} = useDocusaurusContext();
-  const {
-    favicon,
-    title: siteTitle,
-    themeConfig: {image: defaultImage, metadatas},
-    url: siteUrl,
-  } = siteConfig;
+  const {favicon, title: siteTitle, url: siteUrl} = siteConfig;
   const {
     children,
     title,
@@ -33,6 +29,7 @@ function Layout(props: Props): JSX.Element {
     keywords,
     permalink,
   } = props;
+  const {image: defaultImage, metadatas} = useThemeConfig();
   const metaTitle = title ? `${title} | ${siteTitle}` : siteTitle;
 
   const metaImage = image || defaultImage;
diff --git a/packages/docusaurus-theme-bootstrap/src/theme/Navbar/index.tsx b/packages/docusaurus-theme-bootstrap/src/theme/Navbar/index.tsx
index 6e27f1a3d5..04c874a710 100644
--- a/packages/docusaurus-theme-bootstrap/src/theme/Navbar/index.tsx
+++ b/packages/docusaurus-theme-bootstrap/src/theme/Navbar/index.tsx
@@ -7,7 +7,7 @@
 
 import React, {useState, useCallback} from 'react';
 import Link from '@docusaurus/Link';
-import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
+import {useThemeConfig} from '@docusaurus/theme-common';
 import useBaseUrl from '@docusaurus/useBaseUrl';
 import useLogo from '@theme/hooks/useLogo';
 import {
@@ -18,6 +18,16 @@ import {
   NavItem as NavItemBase,
 } from 'reactstrap';
 
+interface NavItemProps {
+  activeBasePath?: string;
+  activeBaseRegex?: RegExp;
+  href?: string;
+  label?: string;
+  to?: string;
+  activeClassName?: string;
+  prependBaseUrlToHref?: boolean;
+}
+
 function NavItem({
   activeBasePath,
   activeBaseRegex,
@@ -27,7 +37,7 @@ function NavItem({
   activeClassName = 'nav-link text-info',
   prependBaseUrlToHref,
   ...props
-}) {
+}: NavItemProps) {
   const toUrl = useBaseUrl(to);
   const activeBaseUrl = useBaseUrl(activeBasePath);
   const normalizedHref = useBaseUrl(href, {forcePrependBaseUrl: true});
@@ -63,12 +73,7 @@ function NavItem({
 }
 
 function Navbar(): JSX.Element {
-  const {
-    siteConfig: {
-      themeConfig: {navbar: {title = '', items: links = []} = {}},
-    },
-    isClient,
-  } = useDocusaurusContext();
+  const {navbar: {title = '', items: links = []} = {}} = useThemeConfig();
 
   const [navbarShown, setNavbarShown] = useState(false);
   const handleNavbarToggle = useCallback(() => {
@@ -86,7 +91,6 @@ function Navbar(): JSX.Element {
       <Link to={logoLink} {...logoLinkProps}>
         {logoImageUrl != null && (
           <img
-            key={isClient}
             width="50"
             height="50"
             style={{
diff --git a/packages/docusaurus-theme-bootstrap/src/theme/hooks/useLogo.ts b/packages/docusaurus-theme-bootstrap/src/theme/hooks/useLogo.ts
index 886ab6109f..611b328f38 100644
--- a/packages/docusaurus-theme-bootstrap/src/theme/hooks/useLogo.ts
+++ b/packages/docusaurus-theme-bootstrap/src/theme/hooks/useLogo.ts
@@ -5,19 +5,19 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
+import {useThemeConfig} from '@docusaurus/theme-common';
 import useBaseUrl from '@docusaurus/useBaseUrl';
 import isInternalUrl from '@docusaurus/isInternalUrl';
 import type {LogoLinkProps, useLogoReturns} from '@theme/hooks/useLogo';
 
 const useLogo = (): useLogoReturns => {
   const {
-    siteConfig: {themeConfig: {navbar: {logo = {}} = {}} = {}} = {},
-  } = useDocusaurusContext();
-  const logoLink = useBaseUrl(logo.href || '/');
+    navbar: {logo},
+  } = useThemeConfig();
+  const logoLink = useBaseUrl(logo?.href || '/');
   let logoLinkProps: LogoLinkProps = {};
 
-  if (logo.target) {
+  if (logo?.target) {
     logoLinkProps = {target: logo.target};
   } else if (!isInternalUrl(logoLink)) {
     logoLinkProps = {
@@ -25,13 +25,13 @@ const useLogo = (): useLogoReturns => {
       target: '_blank',
     };
   }
-  const logoImageUrl = useBaseUrl(logo.src);
+  const logoImageUrl = useBaseUrl(logo?.src);
 
   return {
     logoLink,
     logoLinkProps,
     logoImageUrl,
-    logoAlt: logo.alt,
+    logoAlt: logo?.alt ?? '',
   };
 };
 
diff --git a/packages/docusaurus-theme-classic/src/theme/CodeBlock/index.tsx b/packages/docusaurus-theme-classic/src/theme/CodeBlock/index.tsx
index 0fa58aff97..086186bb8b 100644
--- a/packages/docusaurus-theme-classic/src/theme/CodeBlock/index.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/CodeBlock/index.tsx
@@ -129,14 +129,10 @@ export default function CodeBlock({
     highlightLines = rangeParser(highlightLinesRange).filter((n) => n > 0);
   }
 
-  let language =
-    languageClassName &&
-    // Force Prism's language union type to `any` because it does not contain all available languages
-    // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    ((languageClassName.replace(/language-/, '') as Language) as any);
+  let language = languageClassName?.replace(/language-/, '') as Language;
 
   if (!language && prism.defaultLanguage) {
-    language = prism.defaultLanguage;
+    language = prism.defaultLanguage as Language;
   }
 
   // only declaration OR directive highlight can be used for a block
diff --git a/packages/docusaurus-theme-classic/src/theme/DocPage/index.tsx b/packages/docusaurus-theme-classic/src/theme/DocPage/index.tsx
index 6a73a492ef..fde80d83a3 100644
--- a/packages/docusaurus-theme-classic/src/theme/DocPage/index.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/DocPage/index.tsx
@@ -57,7 +57,7 @@ function DocPageContent({
 
   return (
     <Layout
-      key={isClient}
+      key={`${isClient}`} // TODO seems suspicious
       wrapperClassName={ThemeClassNames.wrapper.docPages}
       pageClassName={ThemeClassNames.page.docPage}
       searchMetadatas={{
diff --git a/packages/docusaurus-theme-classic/src/theme/LayoutHead/index.tsx b/packages/docusaurus-theme-classic/src/theme/LayoutHead/index.tsx
index d3a05c7f4d..6c3aeff479 100644
--- a/packages/docusaurus-theme-classic/src/theme/LayoutHead/index.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/LayoutHead/index.tsx
@@ -16,6 +16,7 @@ import {
   DEFAULT_SEARCH_TAG,
   useTitleFormatter,
   useAlternatePageUtils,
+  useThemeConfig,
 } from '@docusaurus/theme-common';
 import {useLocation} from '@docusaurus/router';
 
@@ -83,12 +84,10 @@ function CanonicalUrlHeaders({permalink}: {permalink?: string}) {
 
 export default function LayoutHead(props: Props): JSX.Element {
   const {
-    siteConfig: {
-      favicon,
-      themeConfig: {metadatas, image: defaultImage},
-    },
+    siteConfig: {favicon},
     i18n: {currentLocale, localeConfigs},
   } = useDocusaurusContext();
+  const {metadatas, image: defaultImage} = useThemeConfig();
   const {title, description, image, keywords, searchMetadatas} = props;
   const faviconUrl = useBaseUrl(favicon);
   const pageTitle = useTitleFormatter(title);
diff --git a/packages/docusaurus-theme-classic/src/theme/Logo/index.tsx b/packages/docusaurus-theme-classic/src/theme/Logo/index.tsx
index 90cf8d558a..82c208f592 100644
--- a/packages/docusaurus-theme-classic/src/theme/Logo/index.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/Logo/index.tsx
@@ -12,17 +12,16 @@ import Link from '@docusaurus/Link';
 import ThemedImage from '@theme/ThemedImage';
 import useBaseUrl from '@docusaurus/useBaseUrl';
 import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
+import {useThemeConfig} from '@docusaurus/theme-common';
 
 const Logo = (props: Props): JSX.Element => {
   const {
-    siteConfig: {
-      title,
-      themeConfig: {
-        navbar: {title: navbarTitle, logo = {src: ''}},
-      },
-    },
+    siteConfig: {title},
     isClient,
   } = useDocusaurusContext();
+  const {
+    navbar: {title: navbarTitle, logo = {src: ''}},
+  } = useThemeConfig();
 
   const {imageClassName, titleClassName, ...propsRest} = props;
   const logoLink = useBaseUrl(logo.href || '/');
@@ -38,7 +37,7 @@ const Logo = (props: Props): JSX.Element => {
       {...(logo.target && {target: logo.target})}>
       {logo.src && (
         <ThemedImage
-          key={isClient}
+          key={`${isClient}`} // TODO seems suspicious
           className={imageClassName}
           sources={sources}
           alt={logo.alt || navbarTitle || title}
diff --git a/packages/docusaurus-theme-classic/src/theme/NavbarItem/LocaleDropdownNavbarItem.tsx b/packages/docusaurus-theme-classic/src/theme/NavbarItem/LocaleDropdownNavbarItem.tsx
index 82877b72ae..c278a72eca 100644
--- a/packages/docusaurus-theme-classic/src/theme/NavbarItem/LocaleDropdownNavbarItem.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/NavbarItem/LocaleDropdownNavbarItem.tsx
@@ -11,6 +11,7 @@ import IconLanguage from '@theme/IconLanguage';
 import type {Props} from '@theme/NavbarItem/LocaleDropdownNavbarItem';
 import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
 import {useAlternatePageUtils} from '@docusaurus/theme-common';
+import type {LinkLikeNavbarItemProps} from '@theme/NavbarItem';
 
 export default function LocaleDropdownNavbarItem({
   mobile,
@@ -23,25 +24,27 @@ export default function LocaleDropdownNavbarItem({
   } = useDocusaurusContext();
   const alternatePageUtils = useAlternatePageUtils();
 
-  function getLocaleLabel(locale) {
+  function getLocaleLabel(locale: string) {
     return localeConfigs[locale].label;
   }
 
-  const localeItems = locales.map((locale) => {
-    const to = `pathname://${alternatePageUtils.createUrl({
-      locale,
-      fullyQualified: false,
-    })}`;
-    return {
-      isNavLink: true,
-      label: getLocaleLabel(locale),
-      to,
-      target: '_self',
-      autoAddBaseUrl: false,
-      className: locale === currentLocale ? 'dropdown__link--active' : '',
-      style: {textTransform: 'capitalize'},
-    };
-  });
+  const localeItems = locales.map(
+    (locale): LinkLikeNavbarItemProps => {
+      const to = `pathname://${alternatePageUtils.createUrl({
+        locale,
+        fullyQualified: false,
+      })}`;
+      return {
+        isNavLink: true,
+        label: getLocaleLabel(locale),
+        to,
+        target: '_self',
+        autoAddBaseUrl: false,
+        className: locale === currentLocale ? 'dropdown__link--active' : '',
+        style: {textTransform: 'capitalize'},
+      };
+    },
+  );
 
   const items = [...dropdownItemsBefore, ...localeItems, ...dropdownItemsAfter];
 
diff --git a/packages/docusaurus-theme-classic/src/theme/prism-include-languages.ts b/packages/docusaurus-theme-classic/src/theme/prism-include-languages.ts
index 0a0a7da475..22a6238114 100644
--- a/packages/docusaurus-theme-classic/src/theme/prism-include-languages.ts
+++ b/packages/docusaurus-theme-classic/src/theme/prism-include-languages.ts
@@ -12,12 +12,13 @@ import type * as PrismNamespace from 'prismjs';
 const prismIncludeLanguages = (PrismObject: typeof PrismNamespace): void => {
   if (ExecutionEnvironment.canUseDOM) {
     const {
-      themeConfig: {prism: {additionalLanguages = []} = {}},
+      themeConfig: {prism = {}},
     } = siteConfig;
+    const {additionalLanguages = []} = prism as {additionalLanguages: string[]};
 
     window.Prism = PrismObject;
 
-    additionalLanguages.forEach((lang: string) => {
+    additionalLanguages.forEach((lang) => {
       require(`prismjs/components/prism-${lang}`); // eslint-disable-line
     });
 
diff --git a/packages/docusaurus-theme-common/src/components/Collapsible/index.tsx b/packages/docusaurus-theme-common/src/components/Collapsible/index.tsx
index 08b0d37477..de1de266a0 100644
--- a/packages/docusaurus-theme-common/src/components/Collapsible/index.tsx
+++ b/packages/docusaurus-theme-common/src/components/Collapsible/index.tsx
@@ -120,7 +120,7 @@ function useCollapseAnimation({
 
     el.style.willChange = 'height';
 
-    function startAnimation(): () => void {
+    function startAnimation() {
       const animationFrame = requestAnimationFrame(() => {
         // When collapsing
         if (collapsed) {
@@ -182,6 +182,7 @@ function CollapsibleBase({
   disableSSRStyle,
 }: CollapsibleBaseProps) {
   // any because TS is a pain for HTML element refs, see https://twitter.com/sebastienlorber/status/1412784677795110914
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   const collapsibleRef = useRef<any>(null);
 
   useCollapseAnimation({collapsibleRef, collapsed, animation});
@@ -191,7 +192,7 @@ function CollapsibleBase({
       // @ts-expect-error: see https://twitter.com/sebastienlorber/status/1412784677795110914
       ref={collapsibleRef}
       style={disableSSRStyle ? undefined : getSSRStyle(collapsed)}
-      onTransitionEnd={(e) => {
+      onTransitionEnd={(e: React.TransitionEvent) => {
         if (e.propertyName !== 'height') {
           return;
         }
diff --git a/packages/docusaurus-theme-common/src/utils/generalUtils.ts b/packages/docusaurus-theme-common/src/utils/generalUtils.ts
index 14ab2b24b9..240ac444af 100644
--- a/packages/docusaurus-theme-common/src/utils/generalUtils.ts
+++ b/packages/docusaurus-theme-common/src/utils/generalUtils.ts
@@ -7,8 +7,8 @@
 import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
 
 export const useTitleFormatter = (title?: string | undefined): string => {
-  const {siteConfig = {}} = useDocusaurusContext();
-  const {title: siteTitle, titleDelimiter = '|'} = siteConfig;
+  const {siteConfig} = useDocusaurusContext();
+  const {title: siteTitle, titleDelimiter} = siteConfig;
   return title && title.trim().length
     ? `${title.trim()} ${titleDelimiter} ${siteTitle}`
     : siteTitle;
diff --git a/packages/docusaurus-types/src/index.d.ts b/packages/docusaurus-types/src/index.d.ts
index 4c7a13915b..81dc328de1 100644
--- a/packages/docusaurus-types/src/index.d.ts
+++ b/packages/docusaurus-types/src/index.d.ts
@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// ESLint doesn't understand types dependencies in d.ts
-// eslint-disable-next-line import/no-extraneous-dependencies
 import type {RuleSetRule, Configuration} from 'webpack';
 import type {Command} from 'commander';
 import type {ParsedUrlQueryInput} from 'querystring';
@@ -346,7 +344,7 @@ export interface RouteConfig {
   routes?: RouteConfig[];
   exact?: boolean;
   priority?: number;
-  [propName: string]: any;
+  [propName: string]: unknown;
 }
 
 // Aliases used for Webpack resolution (when using docusaurus swizzle)
diff --git a/packages/docusaurus/src/client/prefetch.ts b/packages/docusaurus/src/client/prefetch.ts
index 5f14ccc3b3..d86ec70bda 100644
--- a/packages/docusaurus/src/client/prefetch.ts
+++ b/packages/docusaurus/src/client/prefetch.ts
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-function support(feature) {
+function support(feature: string) {
   if (typeof document === 'undefined') {
     return false;
   }
@@ -65,7 +65,7 @@ const supportedPrefetchStrategy = support('prefetch')
   ? linkPrefetchStrategy
   : xhrPrefetchStrategy;
 
-const preFetched = {};
+const preFetched: Record<string, boolean> = {};
 
 function prefetch(url: string): Promise<void> {
   return new Promise((resolve) => {
@@ -79,7 +79,6 @@ function prefetch(url: string): Promise<void> {
         resolve();
         preFetched[url] = true;
       })
-      // eslint-disable-next-line @typescript-eslint/no-empty-function
       .catch(() => {}); // 404s are logged to the console anyway.
   });
 }
diff --git a/packages/docusaurus/src/client/serverEntry.js b/packages/docusaurus/src/client/serverEntry.js
index 7e2eafc355..362eb2c642 100644
--- a/packages/docusaurus/src/client/serverEntry.js
+++ b/packages/docusaurus/src/client/serverEntry.js
@@ -18,9 +18,7 @@ import path from 'path';
 import fs from 'fs-extra';
 import routes from '@generated/routes';
 import packageJson from '../../package.json';
-// eslint-disable-next-line import/no-unresolved
 import preload from './preload';
-// eslint-disable-next-line import/no-unresolved
 import App from './App';
 import {
   createStatefulLinksCollector,
diff --git a/packages/docusaurus/src/server/routes.ts b/packages/docusaurus/src/server/routes.ts
index 18e96d7ddf..9f3ed811c1 100644
--- a/packages/docusaurus/src/server/routes.ts
+++ b/packages/docusaurus/src/server/routes.ts
@@ -128,7 +128,6 @@ export default async function loadRoutes(
       modules = {},
       routes: subroutes,
       exact,
-      // eslint-disable-next-line @typescript-eslint/no-unused-vars
       priority,
       ...props
     } = routeConfig;
diff --git a/packages/docusaurus/src/webpack/__tests__/base.test.ts b/packages/docusaurus/src/webpack/__tests__/base.test.ts
index 6558471f58..6f9dd9821f 100644
--- a/packages/docusaurus/src/webpack/__tests__/base.test.ts
+++ b/packages/docusaurus/src/webpack/__tests__/base.test.ts
@@ -85,7 +85,7 @@ describe('base webpack config', () => {
     siteConfig: {},
     baseUrl: '',
     generatedFilesDir: '',
-    routesPaths: '',
+    routesPaths: [''],
     i18n: {
       currentLocale: 'en',
     },
diff --git a/packages/docusaurus/src/webpack/__tests__/utils.test.ts b/packages/docusaurus/src/webpack/__tests__/utils.test.ts
index 4dc700fb0a..a3b3509878 100644
--- a/packages/docusaurus/src/webpack/__tests__/utils.test.ts
+++ b/packages/docusaurus/src/webpack/__tests__/utils.test.ts
@@ -285,7 +285,6 @@ describe('extending PostCSS', () => {
     expect(postCssLoader1.loader).toEqual('postcss-loader-1');
 
     const pluginNames1 = postCssLoader1.options.postcssOptions.plugins.map(
-      // @ts-expect-error: relax type
       (p: unknown) => p[0],
     );
     expect(pluginNames1).toHaveLength(4);
@@ -301,7 +300,6 @@ describe('extending PostCSS', () => {
     expect(postCssLoader2.loader).toEqual('postcss-loader-2');
 
     const pluginNames2 = postCssLoader2.options.postcssOptions.plugins.map(
-      // @ts-expect-error: relax type
       (p: unknown) => p[0],
     );
     expect(pluginNames2).toHaveLength(4);
diff --git a/packages/docusaurus/src/webpack/plugins/CleanWebpackPlugin.ts b/packages/docusaurus/src/webpack/plugins/CleanWebpackPlugin.ts
index 55c2b20146..6df3e37a00 100644
--- a/packages/docusaurus/src/webpack/plugins/CleanWebpackPlugin.ts
+++ b/packages/docusaurus/src/webpack/plugins/CleanWebpackPlugin.ts
@@ -117,7 +117,6 @@ class CleanWebpackPlugin {
 
   apply(compiler: Compiler): void {
     if (!compiler.options.output || !compiler.options.output.path) {
-      // eslint-disable-next-line no-console
       console.warn(
         'clean-webpack-plugin: options.output.path not defined. Plugin disabled...',
       );
@@ -163,7 +162,6 @@ class CleanWebpackPlugin {
      */
     if (stats.hasErrors()) {
       if (this.verbose) {
-        // eslint-disable-next-line no-console
         console.warn('clean-webpack-plugin: pausing due to webpack errors');
       }
 
@@ -233,7 +231,6 @@ class CleanWebpackPlugin {
            * https://github.com/webpack/webpack/issues/1904
            * https://github.com/johnagan/clean-webpack-plugin/issues/11
            */
-          // eslint-disable-next-line no-console
           console.warn(`clean-webpack-plugin: removed ${filename}`);
         });
       }
diff --git a/website/docs/docusaurus-core.md b/website/docs/docusaurus-core.md
index ea580e0092..841fcee94d 100644
--- a/website/docs/docusaurus-core.md
+++ b/website/docs/docusaurus-core.md
@@ -235,9 +235,25 @@ interface DocusaurusSiteMetadata {
   readonly pluginVersions: Record<string, DocusaurusPluginVersionInformation>;
 }
 
+interface I18nLocaleConfig {
+  label: string;
+  direction: string;
+}
+
+interface I18n {
+  defaultLocale: string;
+  locales: [string, ...string[]];
+  currentLocale: string;
+  localeConfigs: Record<string, I18nLocaleConfig>;
+}
+
 interface DocusaurusContext {
   siteConfig: DocusaurusConfig;
   siteMetadata: DocusaurusSiteMetadata;
+  globalData: Record<string, unknown>;
+  i18n: I18n;
+  codeTranslations: Record<string, string>;
+  isClient: boolean;
 }
 ```