diff --git a/examples/discover_extender/public/plugin.tsx b/examples/discover_extender/public/plugin.tsx
index ea8256a8bbc27..9cd01e43c8dbb 100644
--- a/examples/discover_extender/public/plugin.tsx
+++ b/examples/discover_extender/public/plugin.tsx
@@ -29,8 +29,8 @@ export class DiscoverExtenderPlugin implements Plugin {
   start(core: CoreStart, plugins: DiscoverExtenderStartPlugins) {
     const { discover } = plugins;
 
-    discover.registerExtensions('default', ({ extensions }) => {
-      extensions.set({
+    discover.customize('default', ({ customizations }) => {
+      customizations.set({
         id: 'top_nav',
         defaultMenu: {
           options: { order: 100 },
@@ -58,7 +58,7 @@ export class DiscoverExtenderPlugin implements Plugin {
 
       return () => {
         // eslint-disable-next-line no-console
-        console.log('Cleaning up Document explorer extensions');
+        console.log('Cleaning up Document explorer customizations');
       };
     });
 
@@ -70,8 +70,8 @@ export class DiscoverExtenderPlugin implements Plugin {
       isOptionsOpen = false;
     };
 
-    discover.registerExtensions('extender', async ({ extensions, stateContainer }) => {
-      extensions.set({
+    discover.customize('extender', async ({ customizations, stateContainer }) => {
+      customizations.set({
         id: 'top_nav',
         defaultMenu: {
           options: { disabled: true },
@@ -154,7 +154,7 @@ export class DiscoverExtenderPlugin implements Plugin {
         ],
       });
 
-      extensions.set({
+      customizations.set({
         id: 'search_bar',
         CustomDataViewPicker: () => {
           const [isPopoverOpen, setIsPopoverOpen] = useState(false);
@@ -204,7 +204,7 @@ export class DiscoverExtenderPlugin implements Plugin {
         },
       });
 
-      extensions.set({
+      customizations.set({
         id: 'field_popover',
         CustomBottomButton: () => (
           <EuiButton
@@ -220,7 +220,7 @@ export class DiscoverExtenderPlugin implements Plugin {
 
       const { MoreMenuCell } = await import('./more_menu_cell');
 
-      extensions.set({
+      customizations.set({
         id: 'data_grid',
         defaultLeadingControlColumns: {
           select: { disabled: true },
@@ -241,7 +241,7 @@ export class DiscoverExtenderPlugin implements Plugin {
 
       return () => {
         // eslint-disable-next-line no-console
-        console.log('Cleaning up Logs explorer extensions');
+        console.log('Cleaning up Logs explorer customizations');
       };
     });
   }
diff --git a/src/plugins/discover/public/application/discover_router.tsx b/src/plugins/discover/public/application/discover_router.tsx
index c7a87b4996f92..8fafbed030937 100644
--- a/src/plugins/discover/public/application/discover_router.tsx
+++ b/src/plugins/discover/public/application/discover_router.tsx
@@ -18,12 +18,12 @@ import { DiscoverMainRoute } from './main';
 import { NotFoundRoute } from './not_found';
 import { DiscoverServices } from '../build_services';
 import { ViewAlertRoute } from './view_alert';
-import type { RegisterExtensions } from '../extensions/types';
-import type { DiscoverProfileRegistry } from '../extensions/profile_registry';
+import type { CustomizationCallback } from '../customizations/types';
+import type { DiscoverProfileRegistry } from '../customizations/profile_registry';
 
 interface DiscoverRoutesProps {
   prefix?: string;
-  registerExtensions: RegisterExtensions[];
+  customizationCallbacks: CustomizationCallback[];
   isDev: boolean;
 }
 
@@ -70,14 +70,18 @@ interface CustomDiscoverRoutesProps {
 
 const CustomDiscoverRoutes = ({ profileRegistry, ...props }: CustomDiscoverRoutesProps) => {
   const { profile } = useParams<{ profile: string }>();
-  const registerExtensions = useMemo(
-    () => profileRegistry.get(profile)?.registerExtensions,
+  const customizationCallbacks = useMemo(
+    () => profileRegistry.get(profile)?.customizationCallbacks,
     [profile, profileRegistry]
   );
 
-  if (registerExtensions) {
+  if (customizationCallbacks) {
     return (
-      <DiscoverRoutes prefix={`/p/${profile}`} registerExtensions={registerExtensions} {...props} />
+      <DiscoverRoutes
+        prefix={`/p/${profile}`}
+        customizationCallbacks={customizationCallbacks}
+        {...props}
+      />
     );
   }
 
@@ -97,8 +101,8 @@ export const DiscoverRouter = ({
   profileRegistry,
   ...routeProps
 }: DiscoverRouterProps) => {
-  const registerDefaultExtensions = useMemo(
-    () => profileRegistry.get('default')?.registerExtensions ?? [],
+  const customizationCallbacks = useMemo(
+    () => profileRegistry.get('default')?.customizationCallbacks ?? [],
     [profileRegistry]
   );
 
@@ -111,7 +115,7 @@ export const DiscoverRouter = ({
               <CustomDiscoverRoutes profileRegistry={profileRegistry} {...routeProps} />
             </Route>
             <Route path="/">
-              <DiscoverRoutes registerExtensions={registerDefaultExtensions} {...routeProps} />
+              <DiscoverRoutes customizationCallbacks={customizationCallbacks} {...routeProps} />
             </Route>
           </Switch>
         </Router>
diff --git a/src/plugins/discover/public/application/index.tsx b/src/plugins/discover/public/application/index.tsx
index a4262593ccc5a..b8a24be2b2fcc 100644
--- a/src/plugins/discover/public/application/index.tsx
+++ b/src/plugins/discover/public/application/index.tsx
@@ -11,7 +11,7 @@ import { i18n } from '@kbn/i18n';
 import { toMountPoint, wrapWithTheme } from '@kbn/kibana-react-plugin/public';
 import { DiscoverRouter } from './discover_router';
 import { DiscoverServices } from '../build_services';
-import type { DiscoverProfileRegistry } from '../extensions/profile_registry';
+import type { DiscoverProfileRegistry } from '../customizations/profile_registry';
 
 export interface RenderAppProps {
   element: HTMLElement;
diff --git a/src/plugins/discover/public/application/main/components/layout/discover_documents.tsx b/src/plugins/discover/public/application/main/components/layout/discover_documents.tsx
index 3d496f4a8e529..895a499d94f27 100644
--- a/src/plugins/discover/public/application/main/components/layout/discover_documents.tsx
+++ b/src/plugins/discover/public/application/main/components/layout/discover_documents.tsx
@@ -44,7 +44,7 @@ import { getRawRecordType } from '../../utils/get_raw_record_type';
 import { DiscoverGridFlyout } from '../../../../components/discover_grid/discover_grid_flyout';
 import { DocViewer } from '../../../../services/doc_views/components/doc_viewer';
 import { useSavedSearchInitial } from '../../services/discover_state_provider';
-import { useDiscoverExtension } from '../../../../extensions/extension_provider';
+import { useDiscoverCustomization } from '../../../../customizations/customization_provider';
 
 const containerStyles = css`
   position: relative;
@@ -179,8 +179,8 @@ function DiscoverDocumentsComponent({
     [isPlainRecord, uiSettings, dataView.timeFieldName]
   );
 
-  const dataGridExtension = useDiscoverExtension('data_grid');
-  const defaultControlColumns = dataGridExtension?.defaultLeadingControlColumns;
+  const dataGridCustomization = useDiscoverCustomization('data_grid');
+  const defaultControlColumns = dataGridCustomization?.defaultLeadingControlColumns;
 
   const controlColumnIds = useMemo(() => {
     const ids: string[] = [];
@@ -190,8 +190,8 @@ function DiscoverDocumentsComponent({
   }, [defaultControlColumns?.expand?.disabled, defaultControlColumns?.select?.disabled]);
 
   const customControlColumns = useMemo(
-    () => dataGridExtension?.getLeadingControlColumns?.(),
-    [dataGridExtension]
+    () => dataGridCustomization?.getLeadingControlColumns?.(),
+    [dataGridCustomization]
   );
 
   if (isDataViewLoading || (isEmptyDataResult && isDataLoading)) {
diff --git a/src/plugins/discover/public/application/main/components/sidebar/discover_field.tsx b/src/plugins/discover/public/application/main/components/sidebar/discover_field.tsx
index 0018c35f20447..ce1382d9e0e5e 100644
--- a/src/plugins/discover/public/application/main/components/sidebar/discover_field.tsx
+++ b/src/plugins/discover/public/application/main/components/sidebar/discover_field.tsx
@@ -25,7 +25,7 @@ import { DragDrop } from '@kbn/dom-drag-drop';
 import { DiscoverFieldStats } from './discover_field_stats';
 import { PLUGIN_ID } from '../../../../../common';
 import { getUiActions } from '../../../../kibana_services';
-import { useDiscoverExtension } from '../../../../extensions/extension_provider';
+import { useDiscoverCustomization } from '../../../../customizations/customization_provider';
 
 interface GetCommonFieldItemButtonPropsParams {
   field: DataViewField;
@@ -258,7 +258,7 @@ function DiscoverFieldComponent({
     [field.name]
   );
 
-  const fieldPopoverExtension = useDiscoverExtension('field_popover');
+  const fieldPopoverCustomization = useDiscoverCustomization('field_popover');
 
   const renderPopover = () => {
     return (
diff --git a/src/plugins/discover/public/application/main/components/top_nav/discover_topnav.tsx b/src/plugins/discover/public/application/main/components/top_nav/discover_topnav.tsx
index b033561495acd..b7607d565b461 100644
--- a/src/plugins/discover/public/application/main/components/top_nav/discover_topnav.tsx
+++ b/src/plugins/discover/public/application/main/components/top_nav/discover_topnav.tsx
@@ -17,7 +17,7 @@ import { getTopNavLinks } from './get_top_nav_links';
 import { getHeaderActionMenuMounter } from '../../../../kibana_services';
 import { DiscoverStateContainer } from '../../services/discover_state';
 import { onSaveSearch } from './on_save_search';
-import { useDiscoverExtension } from '../../../../extensions/extension_provider';
+import { useDiscoverCustomization } from '../../../../customizations/customization_provider';
 
 export interface DiscoverTopNavProps {
   onOpenInspector: () => void;
@@ -109,7 +109,7 @@ export const DiscoverTopNav = ({
     });
   }, [dataViewEditor, stateContainer]);
 
-  const topNavExtension = useDiscoverExtension('top_nav');
+  const topNavCustomization = useDiscoverCustomization('top_nav');
   const topNavMenu = useMemo(
     () =>
       getTopNavLinks({
@@ -120,7 +120,7 @@ export const DiscoverTopNav = ({
         isPlainRecord,
         adHocDataViews,
         persistDataView,
-        topNavExtension,
+        topNavCustomization,
       }),
     [
       adHocDataViews,
@@ -130,7 +130,7 @@ export const DiscoverTopNav = ({
       persistDataView,
       services,
       stateContainer,
-      topNavExtension,
+      topNavCustomization,
     ]
   );
 
@@ -198,7 +198,7 @@ export const DiscoverTopNav = ({
     [services, stateContainer]
   );
 
-  const searchBarExtension = useDiscoverExtension('search_bar');
+  const searchBarCustomization = useDiscoverCustomization('search_bar');
 
   return (
     <AggregateQueryTopNavMenu
@@ -216,12 +216,12 @@ export const DiscoverTopNav = ({
       showSearchBar={true}
       useDefaultBehaviors={true}
       customDataViewPicker={
-        searchBarExtension?.CustomDataViewPicker ? (
-          <searchBarExtension.CustomDataViewPicker />
+        searchBarCustomization?.CustomDataViewPicker ? (
+          <searchBarCustomization.CustomDataViewPicker />
         ) : undefined
       }
       dataViewPickerComponentProps={
-        searchBarExtension?.CustomDataViewPicker ? undefined : dataViewPickerProps
+        searchBarCustomization?.CustomDataViewPicker ? undefined : dataViewPickerProps
       }
       displayStyle="detached"
       textBasedLanguageModeErrors={
diff --git a/src/plugins/discover/public/application/main/components/top_nav/get_top_nav_links.tsx b/src/plugins/discover/public/application/main/components/top_nav/get_top_nav_links.tsx
index 2fd0e54b34f40..4b6b215216bc8 100644
--- a/src/plugins/discover/public/application/main/components/top_nav/get_top_nav_links.tsx
+++ b/src/plugins/discover/public/application/main/components/top_nav/get_top_nav_links.tsx
@@ -17,7 +17,7 @@ import { onSaveSearch } from './on_save_search';
 import { DiscoverStateContainer } from '../../services/discover_state';
 import { openOptionsPopover } from './open_options_popover';
 import { openAlertsPopover } from './open_alerts_popover';
-import type { TopNavExtension } from '../../../../extensions';
+import type { TopNavCustomization } from '../../../../customizations';
 
 /**
  * Helper function to build the top nav links
@@ -30,7 +30,7 @@ export const getTopNavLinks = ({
   isPlainRecord,
   persistDataView,
   adHocDataViews,
-  topNavExtension,
+  topNavCustomization,
 }: {
   dataView: DataView;
   services: DiscoverServices;
@@ -39,7 +39,7 @@ export const getTopNavLinks = ({
   isPlainRecord: boolean;
   adHocDataViews: DataView[];
   persistDataView: (dataView: DataView) => Promise<DataView | undefined>;
-  topNavExtension: TopNavExtension | undefined;
+  topNavCustomization: TopNavCustomization | undefined;
 }): TopNavMenuData[] => {
   const options = {
     id: 'options',
@@ -200,8 +200,8 @@ export const getTopNavLinks = ({
     },
   };
 
-  const defaultMenu = topNavExtension?.defaultMenu;
-  const entries = topNavExtension?.getMenuItems?.() ?? [];
+  const defaultMenu = topNavCustomization?.defaultMenu;
+  const entries = topNavCustomization?.getMenuItems?.() ?? [];
 
   if (services.capabilities.advancedSettings.save && !defaultMenu?.options?.disabled) {
     entries.push({ data: options, order: defaultMenu?.options?.order ?? 100 });
diff --git a/src/plugins/discover/public/application/main/discover_main_route.tsx b/src/plugins/discover/public/application/main/discover_main_route.tsx
index 90de868f00e82..492cbc9ba745d 100644
--- a/src/plugins/discover/public/application/main/discover_main_route.tsx
+++ b/src/plugins/discover/public/application/main/discover_main_route.tsx
@@ -29,10 +29,10 @@ import { getScopedHistory, getUrlTracker } from '../../kibana_services';
 import { useAlertResultsToast } from './hooks/use_alert_results_toast';
 import { DiscoverMainProvider } from './services/discover_state_provider';
 import {
-  DiscoverExtensionProvider,
-  useDiscoverExtensionRegistry,
-} from '../../extensions/extension_provider';
-import type { RegisterExtensions } from '../../extensions/types';
+  DiscoverCustomizationProvider,
+  useDiscoverCustomizationService,
+} from '../../customizations/customization_provider';
+import type { CustomizationCallback } from '../../customizations/types';
 
 const DiscoverMainAppMemoized = memo(DiscoverMainApp);
 
@@ -41,11 +41,11 @@ interface DiscoverLandingParams {
 }
 
 export interface MainRouteProps {
-  registerExtensions: RegisterExtensions[];
+  customizationCallbacks: CustomizationCallback[];
   isDev: boolean;
 }
 
-export function DiscoverMainRoute({ registerExtensions, isDev }: MainRouteProps) {
+export function DiscoverMainRoute({ customizationCallbacks, isDev }: MainRouteProps) {
   const history = useHistory();
   const services = useDiscoverServices();
   const {
@@ -63,7 +63,10 @@ export function DiscoverMainRoute({ registerExtensions, isDev }: MainRouteProps)
       services,
     })
   );
-  const extensionRegistry = useDiscoverExtensionRegistry({ registerExtensions, stateContainer });
+  const customizationService = useDiscoverCustomizationService({
+    customizationCallbacks,
+    stateContainer,
+  });
   const [error, setError] = useState<Error>();
   const [loading, setLoading] = useState(true);
   const [hasESData, setHasESData] = useState(false);
@@ -252,15 +255,15 @@ export function DiscoverMainRoute({ registerExtensions, isDev }: MainRouteProps)
     return <DiscoverError error={error} />;
   }
 
-  if (loading || !extensionRegistry) {
+  if (loading || !customizationService) {
     return <LoadingIndicator type={hasCustomBranding ? 'spinner' : 'elastic'} />;
   }
 
   return (
-    <DiscoverExtensionProvider value={extensionRegistry}>
+    <DiscoverCustomizationProvider value={customizationService}>
       <DiscoverMainProvider value={stateContainer}>
         <DiscoverMainAppMemoized stateContainer={stateContainer} />
       </DiscoverMainProvider>
-    </DiscoverExtensionProvider>
+    </DiscoverCustomizationProvider>
   );
 }
diff --git a/src/plugins/discover/public/customizations/customization_provider.ts b/src/plugins/discover/public/customizations/customization_provider.ts
new file mode 100644
index 0000000000000..95c21daa5f9b8
--- /dev/null
+++ b/src/plugins/discover/public/customizations/customization_provider.ts
@@ -0,0 +1,63 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { createContext, useContext, useState } from 'react';
+import useObservable from 'react-use/lib/useObservable';
+import { isFunction } from 'lodash';
+import useEffectOnce from 'react-use/lib/useEffectOnce';
+import {
+  createCustomizationService,
+  DiscoverCustomizationId,
+  DiscoverCustomizationService,
+} from '.';
+import type { DiscoverStateContainer } from '../application/main/services/discover_state';
+import type { CustomizationCallback } from './types';
+
+const customizationContext = createContext<DiscoverCustomizationService>(
+  createCustomizationService()
+);
+
+export const DiscoverCustomizationProvider = customizationContext.Provider;
+
+export const useDiscoverCustomizationService = ({
+  customizationCallbacks,
+  stateContainer,
+}: {
+  customizationCallbacks: CustomizationCallback[];
+  stateContainer: DiscoverStateContainer;
+}) => {
+  const [customizationService, setCustomizationService] = useState<DiscoverCustomizationService>();
+
+  useEffectOnce(() => {
+    const customizations = createCustomizationService();
+    const callbacks = customizationCallbacks.map((callback) =>
+      Promise.resolve(callback({ customizations, stateContainer }))
+    );
+    const initialize = () => Promise.all(callbacks).then((result) => result.filter(isFunction));
+
+    initialize().then(() => {
+      setCustomizationService(customizations);
+    });
+
+    return () => {
+      initialize().then((cleanups) => {
+        cleanups.forEach((cleanup) => cleanup());
+      });
+    };
+  });
+
+  return customizationService;
+};
+
+export const useDiscoverCustomization$ = <TCustomizationId extends DiscoverCustomizationId>(
+  id: TCustomizationId
+) => useContext(customizationContext).get$(id);
+
+export const useDiscoverCustomization = <TCustomizationId extends DiscoverCustomizationId>(
+  id: TCustomizationId
+) => useObservable(useDiscoverCustomization$(id));
diff --git a/src/plugins/discover/public/customizations/customization_service.ts b/src/plugins/discover/public/customizations/customization_service.ts
new file mode 100644
index 0000000000000..729eb070589cc
--- /dev/null
+++ b/src/plugins/discover/public/customizations/customization_service.ts
@@ -0,0 +1,82 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { filter, map, Observable, startWith, Subject } from 'rxjs';
+import type {
+  DataGridCustomization,
+  FieldPopoverCustomization,
+  SearchBarCustomization,
+  TopNavCustomization,
+} from './customization_types';
+
+export type DiscoverCustomization =
+  | DataGridCustomization
+  | FieldPopoverCustomization
+  | SearchBarCustomization
+  | TopNavCustomization;
+
+export type DiscoverCustomizationId = DiscoverCustomization['id'];
+
+export interface DiscoverCustomizationService {
+  set: (customization: DiscoverCustomization) => void;
+  get$: <TCustomizationId extends DiscoverCustomizationId>(
+    id: TCustomizationId
+  ) => Observable<Extract<DiscoverCustomization, { id: TCustomizationId }> | undefined>;
+  enable: (id: DiscoverCustomizationId) => void;
+  disable: (id: DiscoverCustomizationId) => void;
+}
+
+interface CustomizationEntry {
+  customization: DiscoverCustomization;
+  enabled: boolean;
+}
+
+export const createCustomizationService = (): DiscoverCustomizationService => {
+  const update$ = new Subject<DiscoverCustomizationId>();
+  const customizations = new Map<DiscoverCustomizationId, CustomizationEntry>();
+
+  return {
+    set: (customization) => {
+      const entry = customizations.get(customization.id);
+      customizations.set(customization.id, {
+        customization,
+        enabled: entry?.enabled ?? true,
+      });
+      update$.next(customization.id);
+    },
+
+    get$: <TCustomizationId extends DiscoverCustomizationId>(id: TCustomizationId) => {
+      return update$.pipe(
+        startWith(id),
+        filter((currentId) => currentId === id),
+        map(() => {
+          const entry = customizations.get(id);
+          if (entry && entry.enabled) {
+            return entry.customization as Extract<DiscoverCustomization, { id: TCustomizationId }>;
+          }
+        })
+      );
+    },
+
+    enable: (id) => {
+      const entry = customizations.get(id);
+      if (entry && !entry.enabled) {
+        entry.enabled = true;
+        update$.next(entry.customization.id);
+      }
+    },
+
+    disable: (id) => {
+      const entry = customizations.get(id);
+      if (entry && entry.enabled) {
+        entry.enabled = false;
+        update$.next(entry.customization.id);
+      }
+    },
+  };
+};
diff --git a/src/plugins/discover/public/extensions/extension_types/data_grid_extension.ts b/src/plugins/discover/public/customizations/customization_types/data_grid_customization.ts
similarity index 94%
rename from src/plugins/discover/public/extensions/extension_types/data_grid_extension.ts
rename to src/plugins/discover/public/customizations/customization_types/data_grid_customization.ts
index 149f7789c354e..a86be9fae142d 100644
--- a/src/plugins/discover/public/extensions/extension_types/data_grid_extension.ts
+++ b/src/plugins/discover/public/customizations/customization_types/data_grid_customization.ts
@@ -17,7 +17,7 @@ export interface DefaultLeadingControlColumns {
   select?: DefaultLeadingControlColumn;
 }
 
-export interface DataGridExtension {
+export interface DataGridCustomization {
   id: 'data_grid';
   defaultLeadingControlColumns?: DefaultLeadingControlColumns;
   getLeadingControlColumns?: () => EuiDataGridControlColumn[];
diff --git a/src/plugins/discover/public/extensions/extension_types/field_popover_extension.ts b/src/plugins/discover/public/customizations/customization_types/field_popover_customization.ts
similarity index 91%
rename from src/plugins/discover/public/extensions/extension_types/field_popover_extension.ts
rename to src/plugins/discover/public/customizations/customization_types/field_popover_customization.ts
index 18c1c168287fa..fd65e2e120dac 100644
--- a/src/plugins/discover/public/extensions/extension_types/field_popover_extension.ts
+++ b/src/plugins/discover/public/customizations/customization_types/field_popover_customization.ts
@@ -8,7 +8,7 @@
 
 import type { ComponentType } from 'react';
 
-export interface FieldPopoverExtension {
+export interface FieldPopoverCustomization {
   id: 'field_popover';
   disableDefaultBottomButton?: boolean;
   CustomBottomButton?: ComponentType;
diff --git a/src/plugins/discover/public/extensions/extension_types/index.ts b/src/plugins/discover/public/customizations/customization_types/index.ts
similarity index 66%
rename from src/plugins/discover/public/extensions/extension_types/index.ts
rename to src/plugins/discover/public/customizations/customization_types/index.ts
index e96917e27367b..470344842c311 100644
--- a/src/plugins/discover/public/extensions/extension_types/index.ts
+++ b/src/plugins/discover/public/customizations/customization_types/index.ts
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-export * from './data_grid_extension';
-export * from './field_popover_extension';
-export * from './search_bar_extension';
-export * from './top_nav_extension';
+export * from './data_grid_customization';
+export * from './field_popover_customization';
+export * from './search_bar_customization';
+export * from './top_nav_customization';
diff --git a/src/plugins/discover/public/extensions/extension_types/search_bar_extension.ts b/src/plugins/discover/public/customizations/customization_types/search_bar_customization.ts
similarity index 91%
rename from src/plugins/discover/public/extensions/extension_types/search_bar_extension.ts
rename to src/plugins/discover/public/customizations/customization_types/search_bar_customization.ts
index b923ef71eb9a3..8117781a95c93 100644
--- a/src/plugins/discover/public/extensions/extension_types/search_bar_extension.ts
+++ b/src/plugins/discover/public/customizations/customization_types/search_bar_customization.ts
@@ -8,7 +8,7 @@
 
 import type { ComponentType } from 'react';
 
-export interface SearchBarExtension {
+export interface SearchBarCustomization {
   id: 'search_bar';
   CustomDataViewPicker?: ComponentType;
 }
diff --git a/src/plugins/discover/public/extensions/extension_types/top_nav_extension.ts b/src/plugins/discover/public/customizations/customization_types/top_nav_customization.ts
similarity index 96%
rename from src/plugins/discover/public/extensions/extension_types/top_nav_extension.ts
rename to src/plugins/discover/public/customizations/customization_types/top_nav_customization.ts
index a138316dd6f60..45288c6a248fb 100644
--- a/src/plugins/discover/public/extensions/extension_types/top_nav_extension.ts
+++ b/src/plugins/discover/public/customizations/customization_types/top_nav_customization.ts
@@ -28,7 +28,7 @@ export interface TopNavMenuItem {
   order: number;
 }
 
-export interface TopNavExtension {
+export interface TopNavCustomization {
   id: 'top_nav';
   defaultMenu?: TopNavDefaultMenu;
   getMenuItems?: () => TopNavMenuItem[];
diff --git a/src/plugins/discover/public/extensions/index.ts b/src/plugins/discover/public/customizations/index.ts
similarity index 81%
rename from src/plugins/discover/public/extensions/index.ts
rename to src/plugins/discover/public/customizations/index.ts
index ad125a998ba0d..78f922c3a5eac 100644
--- a/src/plugins/discover/public/extensions/index.ts
+++ b/src/plugins/discover/public/customizations/index.ts
@@ -6,5 +6,5 @@
  * Side Public License, v 1.
  */
 
-export * from './extension_types';
-export * from './extension_registry';
+export * from './customization_types';
+export * from './customization_service';
diff --git a/src/plugins/discover/public/extensions/profile_aware_locator.ts b/src/plugins/discover/public/customizations/profile_aware_locator.ts
similarity index 100%
rename from src/plugins/discover/public/extensions/profile_aware_locator.ts
rename to src/plugins/discover/public/customizations/profile_aware_locator.ts
diff --git a/src/plugins/discover/public/extensions/profile_registry.ts b/src/plugins/discover/public/customizations/profile_registry.ts
similarity index 88%
rename from src/plugins/discover/public/extensions/profile_registry.ts
rename to src/plugins/discover/public/customizations/profile_registry.ts
index c1aa440d188e6..236cd991f08b1 100644
--- a/src/plugins/discover/public/extensions/profile_registry.ts
+++ b/src/plugins/discover/public/customizations/profile_registry.ts
@@ -6,11 +6,11 @@
  * Side Public License, v 1.
  */
 
-import type { RegisterExtensions } from './types';
+import type { CustomizationCallback } from './types';
 
 export interface DiscoverProfile {
   name: string;
-  registerExtensions: RegisterExtensions[];
+  customizationCallbacks: CustomizationCallback[];
 }
 
 export interface DiscoverProfileRegistry {
diff --git a/src/plugins/discover/public/extensions/types.ts b/src/plugins/discover/public/customizations/types.ts
similarity index 68%
rename from src/plugins/discover/public/extensions/types.ts
rename to src/plugins/discover/public/customizations/types.ts
index e4ccd1fde8620..7c7088306f585 100644
--- a/src/plugins/discover/public/extensions/types.ts
+++ b/src/plugins/discover/public/customizations/types.ts
@@ -7,13 +7,13 @@
  */
 
 import type { DiscoverStateContainer } from '../application/main/services/discover_state';
-import type { DiscoverExtensionRegistry } from './extension_registry';
+import type { DiscoverCustomizationService } from './customization_service';
 
-export interface RegisterExtensionsContext {
-  extensions: DiscoverExtensionRegistry;
+export interface CustomizationCallbackContext {
+  customizations: DiscoverCustomizationService;
   stateContainer: DiscoverStateContainer;
 }
 
-export type RegisterExtensions = (
-  options: RegisterExtensionsContext
+export type CustomizationCallback = (
+  options: CustomizationCallbackContext
 ) => void | (() => void) | Promise<void | (() => void)>;
diff --git a/src/plugins/discover/public/extensions/extension_provider.ts b/src/plugins/discover/public/extensions/extension_provider.ts
deleted file mode 100644
index 5fcaf1e20cf56..0000000000000
--- a/src/plugins/discover/public/extensions/extension_provider.ts
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License
- * 2.0 and the Server Side Public License, v 1; you may not use this file except
- * in compliance with, at your election, the Elastic License 2.0 or the Server
- * Side Public License, v 1.
- */
-
-import { createContext, useContext, useState } from 'react';
-import useObservable from 'react-use/lib/useObservable';
-import { isFunction } from 'lodash';
-import useEffectOnce from 'react-use/lib/useEffectOnce';
-import { createExtensionRegistry, DiscoverExtensionId, DiscoverExtensionRegistry } from '.';
-import type { DiscoverStateContainer } from '../application/main/services/discover_state';
-import type { RegisterExtensions } from './types';
-
-const extensionContext = createContext<DiscoverExtensionRegistry>(createExtensionRegistry());
-
-export const DiscoverExtensionProvider = extensionContext.Provider;
-
-export const useDiscoverExtensionRegistry = ({
-  registerExtensions,
-  stateContainer,
-}: {
-  registerExtensions: RegisterExtensions[];
-  stateContainer: DiscoverStateContainer;
-}) => {
-  const [extensionRegistry, setExtensionRegistry] = useState<DiscoverExtensionRegistry>();
-
-  useEffectOnce(() => {
-    const extensions = createExtensionRegistry();
-    const registrations = registerExtensions.map((register) =>
-      Promise.resolve(register({ extensions, stateContainer }))
-    );
-    const initialize = () => Promise.all(registrations).then((result) => result.filter(isFunction));
-
-    initialize().then(() => {
-      setExtensionRegistry(extensions);
-    });
-
-    return () => {
-      initialize().then((cleanups) => {
-        cleanups.forEach((cleanup) => cleanup());
-      });
-    };
-  });
-
-  return extensionRegistry;
-};
-
-export const useDiscoverExtension$ = <TExtensionId extends DiscoverExtensionId>(id: TExtensionId) =>
-  useContext(extensionContext).get$(id);
-
-export const useDiscoverExtension = <TExtensionId extends DiscoverExtensionId>(id: TExtensionId) =>
-  useObservable(useDiscoverExtension$(id));
diff --git a/src/plugins/discover/public/extensions/extension_registry.ts b/src/plugins/discover/public/extensions/extension_registry.ts
deleted file mode 100644
index 1a8f3335454eb..0000000000000
--- a/src/plugins/discover/public/extensions/extension_registry.ts
+++ /dev/null
@@ -1,79 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License
- * 2.0 and the Server Side Public License, v 1; you may not use this file except
- * in compliance with, at your election, the Elastic License 2.0 or the Server
- * Side Public License, v 1.
- */
-
-import { filter, map, Observable, startWith, Subject } from 'rxjs';
-import type {
-  DataGridExtension,
-  FieldPopoverExtension,
-  SearchBarExtension,
-  TopNavExtension,
-} from './extension_types';
-
-export type DiscoverExtension =
-  | DataGridExtension
-  | FieldPopoverExtension
-  | SearchBarExtension
-  | TopNavExtension;
-
-export type DiscoverExtensionId = DiscoverExtension['id'];
-
-export interface DiscoverExtensionRegistry {
-  set: (extension: DiscoverExtension) => void;
-  get$: <TExtensionId extends DiscoverExtensionId>(
-    id: TExtensionId
-  ) => Observable<Extract<DiscoverExtension, { id: TExtensionId }> | undefined>;
-  enable: (id: DiscoverExtensionId) => void;
-  disable: (id: DiscoverExtensionId) => void;
-}
-
-interface DiscoverExtensionRegistration {
-  extension: DiscoverExtension;
-  enabled: boolean;
-}
-
-export const createExtensionRegistry = (): DiscoverExtensionRegistry => {
-  const update$ = new Subject<DiscoverExtensionId>();
-  const registrations = new Map<DiscoverExtensionId, DiscoverExtensionRegistration>();
-
-  return {
-    set: (extension) => {
-      const registration = registrations.get(extension.id);
-      registrations.set(extension.id, { extension, enabled: registration?.enabled ?? true });
-      update$.next(extension.id);
-    },
-
-    get$: <TExtensionId extends DiscoverExtensionId>(id: TExtensionId) => {
-      return update$.pipe(
-        startWith(id),
-        filter((currentId) => currentId === id),
-        map(() => {
-          const registration = registrations.get(id);
-          if (registration && registration.enabled) {
-            return registration.extension as Extract<DiscoverExtension, { id: TExtensionId }>;
-          }
-        })
-      );
-    },
-
-    enable: (id) => {
-      const registration = registrations.get(id);
-      if (registration && !registration.enabled) {
-        registration.enabled = true;
-        update$.next(registration.extension.id);
-      }
-    },
-
-    disable: (id) => {
-      const registration = registrations.get(id);
-      if (registration && registration.enabled) {
-        registration.enabled = false;
-        update$.next(registration.extension.id);
-      }
-    },
-  };
-};
diff --git a/src/plugins/discover/public/plugin.tsx b/src/plugins/discover/public/plugin.tsx
index 150a378c2cf2c..f114578c8f4de 100644
--- a/src/plugins/discover/public/plugin.tsx
+++ b/src/plugins/discover/public/plugin.tsx
@@ -71,9 +71,9 @@ import {
   DiscoverSingleDocLocatorDefinition,
 } from './application/doc/locator';
 import { DiscoverAppLocator, DiscoverAppLocatorDefinition } from '../common';
-import type { RegisterExtensions } from './extensions/types';
-import { createProfileRegistry } from './extensions/profile_registry';
-import { ProfileAwareLocator } from './extensions/profile_aware_locator';
+import type { CustomizationCallback } from './customizations/types';
+import { createProfileRegistry } from './customizations/profile_registry';
+import { ProfileAwareLocator } from './customizations/profile_aware_locator';
 
 const DocViewerLegacyTable = React.lazy(
   () => import('./services/doc_views/components/doc_viewer_table/legacy')
@@ -158,7 +158,7 @@ export interface DiscoverStart {
    * ```
    */
   readonly locator: undefined | DiscoverAppLocator;
-  readonly registerExtensions: (profileName: string, register: RegisterExtensions) => void;
+  readonly customize: (profileName: string, callback: CustomizationCallback) => void;
 }
 
 /**
@@ -409,12 +409,12 @@ export class DiscoverPlugin
 
     return {
       locator: this.locator,
-      registerExtensions: (profileName: string, register: RegisterExtensions) => {
+      customize: (profileName: string, callback: CustomizationCallback) => {
         const profile = this.profileRegistry.get(profileName) ?? {
           name: profileName,
-          registerExtensions: [],
+          customizationCallbacks: [],
         };
-        profile.registerExtensions.push(register);
+        profile.customizationCallbacks.push(callback);
         this.profileRegistry.set(profile);
       },
     };