diff --git a/.eslintrc.js b/.eslintrc.js
index 8d5b4525d51ba54..4d97d54e2da048c 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -905,6 +905,18 @@ module.exports = {
       },
     },
 
+    /**
+     * Enterprise Search overrides
+     */
+    {
+      files: ['x-pack/plugins/enterprise_search/**/*.{ts,tsx}'],
+      excludedFiles: ['x-pack/plugins/enterprise_search/**/*.{test,mock}.{ts,tsx}'],
+      rules: {
+        'react-hooks/exhaustive-deps': 'off',
+        '@typescript-eslint/no-explicit-any': 'error',
+      },
+    },
+
     /**
      * disable jsx-a11y for kbn-ui-framework
      */
diff --git a/x-pack/plugins/enterprise_search/public/applications/__mocks__/mount_with_context.mock.tsx b/x-pack/plugins/enterprise_search/public/applications/__mocks__/mount_with_context.mock.tsx
index 7d0716ce0cdd0bc..dfcda544459d441 100644
--- a/x-pack/plugins/enterprise_search/public/applications/__mocks__/mount_with_context.mock.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/__mocks__/mount_with_context.mock.tsx
@@ -22,7 +22,7 @@ import { mockLicenseContext } from './license_context.mock';
  *
  * const wrapper = mountWithContext(<Component />, { enterpriseSearchUrl: 'someOverride', license: {} });
  */
-export const mountWithContext = (children, context) => {
+export const mountWithContext = (children: React.ReactNode, context?: object) => {
   return mount(
     <I18nProvider>
       <KibanaContext.Provider value={{ ...mockKibanaContext, ...context }}>
@@ -40,7 +40,7 @@ export const mountWithContext = (children, context) => {
  *
  * Same usage/override functionality as mountWithContext
  */
-export const mountWithKibanaContext = (children, context) => {
+export const mountWithKibanaContext = (children: React.ReactNode, context?: object) => {
   return mount(
     <KibanaContext.Provider value={{ ...mockKibanaContext, ...context }}>
       {children}
diff --git a/x-pack/plugins/enterprise_search/public/applications/__mocks__/shallow_with_i18n.mock.tsx b/x-pack/plugins/enterprise_search/public/applications/__mocks__/shallow_with_i18n.mock.tsx
index 7815bb71fa50e65..ae7d0b09f9872e2 100644
--- a/x-pack/plugins/enterprise_search/public/applications/__mocks__/shallow_with_i18n.mock.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/__mocks__/shallow_with_i18n.mock.tsx
@@ -20,12 +20,11 @@ const { intl } = intlProvider.getChildContext();
  *
  * const wrapper = shallowWithIntl(<Component />);
  */
-export const shallowWithIntl = (children) => {
-  return shallow(<I18nProvider>{children}</I18nProvider>, {
-    context: { intl },
-    childContextTypes: { intl },
-  })
+export const shallowWithIntl = (children: React.ReactNode) => {
+  const context = { context: { intl } };
+
+  return shallow(<I18nProvider>{children}</I18nProvider>, context)
     .childAt(0)
-    .dive()
+    .dive(context)
     .shallow();
 };
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/empty_state.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/empty_state.tsx
index 91b1a4319cbd722..26ed01cc614dc06 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/empty_state.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/empty_state.tsx
@@ -16,7 +16,7 @@ import { EngineOverviewHeader } from '../engine_overview_header';
 
 import './empty_states.scss';
 
-export const EmptyState: React.FC<> = () => {
+export const EmptyState: React.FC = () => {
   const { enterpriseSearchUrl, http } = useContext(KibanaContext) as IKibanaContext;
 
   const buttonProps = {
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/empty_states.test.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/empty_states.test.tsx
index bb37229998ed212..2d2f92c2f7b1f3a 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/empty_states.test.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/empty_states.test.tsx
@@ -39,7 +39,8 @@ describe('NoUserState', () => {
   });
 
   it('renders with username', () => {
-    getUserName.mockImplementationOnce(() => 'dolores-abernathy');
+    (getUserName as jest.Mock).mockImplementationOnce(() => 'dolores-abernathy');
+
     const wrapper = shallowWithIntl(<NoUserState />);
     const prompt = wrapper.find(EuiEmptyPrompt).dive();
     const description1 = prompt.find(FormattedMessage).at(1).dive();
@@ -62,7 +63,7 @@ describe('EmptyState', () => {
 
     button.simulate('click');
     expect(sendTelemetry).toHaveBeenCalled();
-    sendTelemetry.mockClear();
+    (sendTelemetry as jest.Mock).mockClear();
   });
 });
 
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/error_state.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/error_state.tsx
index 039e645a271268a..5891c89c3a022cf 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/error_state.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/error_state.tsx
@@ -16,7 +16,7 @@ import { EngineOverviewHeader } from '../engine_overview_header';
 
 import './empty_states.scss';
 
-export const ErrorState: ReactFC<> = () => {
+export const ErrorState: React.FC = () => {
   const { enterpriseSearchUrl } = useContext(KibanaContext) as IKibanaContext;
 
   return (
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/loading_state.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/loading_state.tsx
index 5c1d0c744f7434a..3d69fe61262734b 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/loading_state.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/loading_state.tsx
@@ -12,7 +12,7 @@ import { EngineOverviewHeader } from '../engine_overview_header';
 
 import './empty_states.scss';
 
-export const LoadingState: React.FC<> = () => {
+export const LoadingState: React.FC = () => {
   return (
     <EuiPage restrictWidth className="engine-overview empty-state">
       <SetBreadcrumbs isRoot />
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/no_user_state.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/no_user_state.tsx
index c1d6c2bcffe41e8..bf728bd43ead02e 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/no_user_state.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/empty_states/no_user_state.tsx
@@ -15,7 +15,7 @@ import { getUserName } from '../../utils/get_username';
 
 import './empty_states.scss';
 
-export const NoUserState: React.FC<> = () => {
+export const NoUserState: React.FC = () => {
   const username = getUserName();
 
   return (
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_overview.test.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_overview.test.tsx
index a9670163e76b822..18cf3dade205685 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_overview.test.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_overview.test.tsx
@@ -8,7 +8,7 @@ import '../../../__mocks__/react_router_history.mock';
 
 import React from 'react';
 import { act } from 'react-dom/test-utils';
-import { render } from 'enzyme';
+import { render, ReactWrapper } from 'enzyme';
 
 import { I18nProvider } from '@kbn/i18n/react';
 import { KibanaContext } from '../../../';
@@ -16,7 +16,7 @@ import { LicenseContext } from '../../../shared/licensing';
 import { mountWithContext, mockKibanaContext } from '../../../__mocks__';
 
 import { EmptyState, ErrorState, NoUserState } from '../empty_states';
-import { EngineTable } from './engine_table';
+import { EngineTable, IEngineTablePagination } from './engine_table';
 
 import { EngineOverview } from './';
 
@@ -25,7 +25,7 @@ describe('EngineOverview', () => {
     it('isLoading', () => {
       // We use render() instead of mount() here to not trigger lifecycle methods (i.e., useEffect)
       // TODO: Consider pulling this out to a renderWithContext mock/helper
-      const wrapper = render(
+      const wrapper: Cheerio = render(
         <I18nProvider>
           <KibanaContext.Provider value={{ http: {} }}>
             <LicenseContext.Provider value={{ license: {} }}>
@@ -85,7 +85,7 @@ describe('EngineOverview', () => {
       },
     };
     const mockApi = jest.fn(() => mockedApiResponse);
-    let wrapper;
+    let wrapper: ReactWrapper;
 
     beforeAll(async () => {
       wrapper = await mountWithApiMock({ get: mockApi });
@@ -105,7 +105,8 @@ describe('EngineOverview', () => {
     });
 
     describe('pagination', () => {
-      const getTablePagination = () => wrapper.find(EngineTable).first().prop('pagination');
+      const getTablePagination: () => IEngineTablePagination = () =>
+        wrapper.find(EngineTable).first().prop('pagination');
 
       it('passes down page data from the API', () => {
         const pagination = getTablePagination();
@@ -156,8 +157,8 @@ describe('EngineOverview', () => {
    * Test helpers
    */
 
-  const mountWithApiMock = async ({ get, license }) => {
-    let wrapper;
+  const mountWithApiMock = async ({ get, license }: { get(): any; license?: object }) => {
+    let wrapper: ReactWrapper | undefined;
     const httpMock = { ...mockKibanaContext.http, get };
 
     // We get a lot of act() warning/errors in the terminal without this.
@@ -166,8 +167,12 @@ describe('EngineOverview', () => {
     await act(async () => {
       wrapper = mountWithContext(<EngineOverview />, { http: httpMock, license });
     });
-    wrapper.update(); // This seems to be required for the DOM to actually update
+    if (wrapper) {
+      wrapper.update(); // This seems to be required for the DOM to actually update
 
-    return wrapper;
+      return wrapper;
+    } else {
+      throw new Error('Could not mount wrapper');
+    }
   };
 });
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_overview.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_overview.tsx
index a1e4a11dc2daf39..479dfe8e61513ac 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_overview.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_overview.tsx
@@ -30,7 +30,7 @@ import { EngineTable } from './engine_table';
 
 import './engine_overview.scss';
 
-export const EngineOverview: ReactFC<> = () => {
+export const EngineOverview: React.FC = () => {
   const { http } = useContext(KibanaContext) as IKibanaContext;
   const { license } = useContext(LicenseContext) as ILicenseContext;
 
@@ -45,12 +45,12 @@ export const EngineOverview: ReactFC<> = () => {
   const [metaEnginesPage, setMetaEnginesPage] = useState(1);
   const [metaEnginesTotal, setMetaEnginesTotal] = useState(0);
 
-  const getEnginesData = async ({ type, pageIndex }) => {
+  const getEnginesData = async ({ type, pageIndex }: IGetEnginesParams) => {
     return await http.get('/api/app_search/engines', {
       query: { type, pageIndex },
     });
   };
-  const setEnginesData = async (params, callbacks) => {
+  const setEnginesData = async (params: IGetEnginesParams, callbacks: ISetEnginesCallbacks) => {
     try {
       const response = await getEnginesData(params);
 
@@ -72,7 +72,7 @@ export const EngineOverview: ReactFC<> = () => {
     const callbacks = { setResults: setEngines, setResultsTotal: setEnginesTotal };
 
     setEnginesData(params, callbacks);
-  }, [enginesPage]); // eslint-disable-line react-hooks/exhaustive-deps
+  }, [enginesPage]);
 
   useEffect(() => {
     if (hasPlatinumLicense(license)) {
@@ -81,7 +81,7 @@ export const EngineOverview: ReactFC<> = () => {
 
       setEnginesData(params, callbacks);
     }
-  }, [license, metaEnginesPage]); // eslint-disable-line react-hooks/exhaustive-deps
+  }, [license, metaEnginesPage]);
 
   if (hasErrorConnecting) return <ErrorState />;
   if (hasNoAccount) return <NoUserState />;
@@ -150,3 +150,16 @@ export const EngineOverview: ReactFC<> = () => {
     </EuiPage>
   );
 };
+
+/**
+ * Type definitions
+ */
+
+interface IGetEnginesParams {
+  type: string;
+  pageIndex: number;
+}
+interface ISetEnginesCallbacks {
+  setResults: React.Dispatch<React.SetStateAction<never[]>>;
+  setResultsTotal: React.Dispatch<React.SetStateAction<number>>;
+}
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_table.test.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_table.test.tsx
index 1665726251bd6eb..46b6e61e352de5b 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_table.test.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_table.test.tsx
@@ -72,9 +72,9 @@ describe('EngineTable', () => {
 
   it('handles empty data', () => {
     const emptyWrapper = mountWithContext(
-      <EngineTable data={[]} pagination={{ totalEngines: 0 }} />
+      <EngineTable data={[]} pagination={{ totalEngines: 0, pageIndex: 0, onPaginate: () => {} }} />
     );
-    const emptyTable = wrapper.find(EuiBasicTable);
+    const emptyTable = emptyWrapper.find(EuiBasicTable);
     expect(emptyTable.prop('pagination').pageIndex).toEqual(0);
   });
 });
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_table.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_table.tsx
index d565856f9675da9..1e58d820dc83b0c 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_table.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview/engine_table.tsx
@@ -5,7 +5,7 @@
  */
 
 import React, { useContext } from 'react';
-import { EuiBasicTable, EuiLink } from '@elastic/eui';
+import { EuiBasicTable, EuiBasicTableColumn, EuiLink } from '@elastic/eui';
 import { FormattedMessage, FormattedDate, FormattedNumber } from '@kbn/i18n/react';
 import { i18n } from '@kbn/i18n';
 
@@ -14,31 +14,33 @@ import { KibanaContext, IKibanaContext } from '../../../index';
 
 import { ENGINES_PAGE_SIZE } from '../../../../../common/constants';
 
-interface IEngineTableProps {
-  data: Array<{
-    name: string;
-    created_at: string;
-    document_count: number;
-    field_count: number;
-  }>;
-  pagination: {
-    totalEngines: number;
-    pageIndex: number;
-    onPaginate(pageIndex: number);
-  };
+export interface IEngineTableData {
+  name: string;
+  created_at: string;
+  document_count: number;
+  field_count: number;
+}
+export interface IEngineTablePagination {
+  totalEngines: number;
+  pageIndex: number;
+  onPaginate(pageIndex: number): void;
+}
+export interface IEngineTableProps {
+  data: IEngineTableData[];
+  pagination: IEngineTablePagination;
 }
-interface IOnChange {
+export interface IOnChange {
   page: {
     index: number;
   };
 }
 
-export const EngineTable: ReactFC<IEngineTableProps> = ({
+export const EngineTable: React.FC<IEngineTableProps> = ({
   data,
-  pagination: { totalEngines, pageIndex = 0, onPaginate },
+  pagination: { totalEngines, pageIndex, onPaginate },
 }) => {
   const { enterpriseSearchUrl, http } = useContext(KibanaContext) as IKibanaContext;
-  const engineLinkProps = (name) => ({
+  const engineLinkProps = (name: string) => ({
     href: `${enterpriseSearchUrl}/as/engines/${name}`,
     target: '_blank',
     onClick: () =>
@@ -50,13 +52,13 @@ export const EngineTable: ReactFC<IEngineTableProps> = ({
       }),
   });
 
-  const columns = [
+  const columns: Array<EuiBasicTableColumn<IEngineTableData>> = [
     {
       field: 'name',
       name: i18n.translate('xpack.enterpriseSearch.appSearch.enginesOverview.table.column.name', {
         defaultMessage: 'Name',
       }),
-      render: (name) => (
+      render: (name: string) => (
         <EuiLink data-test-subj="engineNameLink" {...engineLinkProps(name)}>
           {name}
         </EuiLink>
@@ -65,6 +67,8 @@ export const EngineTable: ReactFC<IEngineTableProps> = ({
       truncateText: true,
       mobileOptions: {
         header: true,
+        // Note: the below props are valid props per https://elastic.github.io/eui/#/tabular-content/tables (Responsive tables), but EUI's types have a bug reporting it as an error
+        // @ts-ignore
         enlarge: true,
         fullWidth: true,
         truncateText: false,
@@ -79,7 +83,7 @@ export const EngineTable: ReactFC<IEngineTableProps> = ({
         }
       ),
       dataType: 'string',
-      render: (dateString) => (
+      render: (dateString: string) => (
         // e.g., January 1, 1970
         <FormattedDate value={new Date(dateString)} year="numeric" month="long" day="numeric" />
       ),
@@ -93,7 +97,7 @@ export const EngineTable: ReactFC<IEngineTableProps> = ({
         }
       ),
       dataType: 'number',
-      render: (number) => <FormattedNumber value={number} />,
+      render: (number: number) => <FormattedNumber value={number} />,
       truncateText: true,
     },
     {
@@ -105,7 +109,7 @@ export const EngineTable: ReactFC<IEngineTableProps> = ({
         }
       ),
       dataType: 'number',
-      render: (number) => <FormattedNumber value={number} />,
+      render: (number: number) => <FormattedNumber value={number} />,
       truncateText: true,
     },
     {
@@ -117,7 +121,7 @@ export const EngineTable: ReactFC<IEngineTableProps> = ({
         }
       ),
       dataType: 'string',
-      render: (name) => (
+      render: (name: string) => (
         <EuiLink {...engineLinkProps(name)}>
           <FormattedMessage
             id="xpack.enterpriseSearch.appSearch.enginesOverview.table.action.manage"
@@ -140,7 +144,7 @@ export const EngineTable: ReactFC<IEngineTableProps> = ({
         totalItemCount: totalEngines,
         hidePerPageOptions: true,
       }}
-      onChange={({ page }): IOnChange => {
+      onChange={({ page }: IOnChange) => {
         const { index } = page;
         onPaginate(index + 1); // Note on paging - App Search's API pages start at 1, EuiBasicTables' pages start at 0
       }}
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview_header/engine_overview_header.test.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview_header/engine_overview_header.test.tsx
index 9663eb4ef61af8e..2e49540270ef070 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview_header/engine_overview_header.test.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview_header/engine_overview_header.test.tsx
@@ -24,8 +24,8 @@ describe('EngineOverviewHeader', () => {
     const wrapper = shallow(<EngineOverviewHeader />);
     const button = wrapper.find('[data-test-subj="launchButton"]');
 
-    expect(button.props().href).toBe('http://localhost:3002/as');
-    expect(button.props().isDisabled).toBeFalsy();
+    expect(button.prop('href')).toBe('http://localhost:3002/as');
+    expect(button.prop('isDisabled')).toBeFalsy();
 
     button.simulate('click');
     expect(sendTelemetry).toHaveBeenCalled();
@@ -35,7 +35,7 @@ describe('EngineOverviewHeader', () => {
     const wrapper = shallow(<EngineOverviewHeader isButtonDisabled />);
     const button = wrapper.find('[data-test-subj="launchButton"]');
 
-    expect(button.props().isDisabled).toBe(true);
-    expect(button.props().href).toBeUndefined();
+    expect(button.prop('isDisabled')).toBe(true);
+    expect(button.prop('href')).toBeUndefined();
   });
 });
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview_header/engine_overview_header.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview_header/engine_overview_header.tsx
index 650a864f5e615ee..9aafa8ec0380c70 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview_header/engine_overview_header.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/engine_overview_header/engine_overview_header.tsx
@@ -5,7 +5,14 @@
  */
 
 import React, { useContext } from 'react';
-import { EuiPageHeader, EuiPageHeaderSection, EuiTitle, EuiButton } from '@elastic/eui';
+import {
+  EuiPageHeader,
+  EuiPageHeaderSection,
+  EuiTitle,
+  EuiButton,
+  EuiButtonProps,
+  EuiLinkProps,
+} from '@elastic/eui';
 import { FormattedMessage } from '@kbn/i18n/react';
 
 import { sendTelemetry } from '../../../shared/telemetry';
@@ -24,7 +31,8 @@ export const EngineOverviewHeader: React.FC<IEngineOverviewHeaderProps> = ({
     fill: true,
     iconType: 'popout',
     'data-test-subj': 'launchButton',
-  };
+  } as EuiButtonProps & EuiLinkProps;
+
   if (isButtonDisabled) {
     buttonProps.isDisabled = true;
   } else {
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/components/setup_guide/setup_guide.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/components/setup_guide/setup_guide.tsx
index 855449b0c0bcdf8..3e290a7777f1c6c 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/components/setup_guide/setup_guide.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/components/setup_guide/setup_guide.tsx
@@ -15,7 +15,6 @@ import {
   EuiFlexItem,
   EuiTitle,
   EuiText,
-  EuiImage,
   EuiIcon,
   EuiSteps,
   EuiCode,
@@ -32,7 +31,7 @@ import { SendAppSearchTelemetry as SendTelemetry } from '../../../shared/telemet
 import GettingStarted from '../../assets/getting_started.png';
 import './setup_guide.scss';
 
-export const SetupGuide: React.FC<> = () => {
+export const SetupGuide: React.FC = () => {
   return (
     <EuiPage className="setup-guide">
       <SetBreadcrumbs text="Setup Guide" />
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/index.test.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/index.test.tsx
index d11c47475089dc4..45e318ca0f9d958 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/index.test.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/index.test.tsx
@@ -18,7 +18,7 @@ import { AppSearch } from './';
 describe('App Search Routes', () => {
   describe('/', () => {
     it('redirects to Setup Guide when enterpriseSearchUrl is not set', () => {
-      useContext.mockImplementationOnce(() => ({ enterpriseSearchUrl: '' }));
+      (useContext as jest.Mock).mockImplementationOnce(() => ({ enterpriseSearchUrl: '' }));
       const wrapper = shallow(<AppSearch />);
 
       expect(wrapper.find(Redirect)).toHaveLength(1);
@@ -26,7 +26,9 @@ describe('App Search Routes', () => {
     });
 
     it('renders Engine Overview when enterpriseSearchUrl is set', () => {
-      useContext.mockImplementationOnce(() => ({ enterpriseSearchUrl: 'https://foo.bar' }));
+      (useContext as jest.Mock).mockImplementationOnce(() => ({
+        enterpriseSearchUrl: 'https://foo.bar',
+      }));
       const wrapper = shallow(<AppSearch />);
 
       expect(wrapper.find(EngineOverview)).toHaveLength(1);
diff --git a/x-pack/plugins/enterprise_search/public/applications/app_search/index.tsx b/x-pack/plugins/enterprise_search/public/applications/app_search/index.tsx
index 9afc3c9fd97616c..8f7142f1631a958 100644
--- a/x-pack/plugins/enterprise_search/public/applications/app_search/index.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/app_search/index.tsx
@@ -12,7 +12,7 @@ import { KibanaContext, IKibanaContext } from '../index';
 import { SetupGuide } from './components/setup_guide';
 import { EngineOverview } from './components/engine_overview';
 
-export const AppSearch: React.FC<> = () => {
+export const AppSearch: React.FC = () => {
   const { enterpriseSearchUrl } = useContext(KibanaContext) as IKibanaContext;
 
   return (
diff --git a/x-pack/plugins/enterprise_search/public/applications/index.test.tsx b/x-pack/plugins/enterprise_search/public/applications/index.test.tsx
index fd88fc32ff4ae72..ef69ba7e40cf36d 100644
--- a/x-pack/plugins/enterprise_search/public/applications/index.test.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/index.test.tsx
@@ -18,14 +18,14 @@ describe('renderApp', () => {
   const config = {};
   const plugins = {
     licensing: licensingMock.createSetup(),
-  };
+  } as any;
 
   beforeEach(() => {
     jest.clearAllMocks();
   });
 
   it('mounts and unmounts UI', () => {
-    const MockApp: React.FC = () => <div className="hello-world">Hello world!</div>;
+    const MockApp = () => <div className="hello-world">Hello world!</div>;
 
     const unmount = renderApp(MockApp, core, params, config, plugins);
     expect(params.element.querySelector('.hello-world')).not.toBeNull();
diff --git a/x-pack/plugins/enterprise_search/public/applications/index.tsx b/x-pack/plugins/enterprise_search/public/applications/index.tsx
index ac6d01f8861756e..b73128c701a414b 100644
--- a/x-pack/plugins/enterprise_search/public/applications/index.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/index.tsx
@@ -6,23 +6,23 @@
 
 import React from 'react';
 import ReactDOM from 'react-dom';
-import { Router, Route, Redirect } from 'react-router-dom';
+import { Router } from 'react-router-dom';
+import { Observable } from 'rxjs';
 
 import { I18nProvider } from '@kbn/i18n/react';
-import { CoreStart, AppMountParams, HttpHandler } from 'src/core/public';
+import { CoreStart, AppMountParameters, HttpSetup, ChromeBreadcrumb } from 'src/core/public';
 import { ClientConfigType, PluginsSetup } from '../plugin';
-import { TSetBreadcrumbs } from './shared/kibana_breadcrumbs';
-import { ILicense } from '../../../../licensing/public';
+import { ILicense } from '../../../licensing/public';
 import { LicenseProvider } from './shared/licensing';
 
 export interface IKibanaContext {
   enterpriseSearchUrl?: string;
-  http(): HttpHandler;
-  setBreadCrumbs(): TSetBreadcrumbs;
+  http: HttpSetup;
+  setBreadcrumbs(crumbs: ChromeBreadcrumb[]): void;
   license$: Observable<ILicense>;
 }
 
-export const KibanaContext = React.createContext();
+export const KibanaContext = React.createContext({});
 
 /**
  * This file serves as a reusable wrapper to share Kibana-level context and other helpers
@@ -31,9 +31,9 @@ export const KibanaContext = React.createContext();
  */
 
 export const renderApp = (
-  App: React.Element,
+  App: React.FC,
   core: CoreStart,
-  params: AppMountParams,
+  params: AppMountParameters,
   config: ClientConfigType,
   plugins: PluginsSetup
 ) => {
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/generate_breadcrumbs.test.ts b/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/generate_breadcrumbs.test.ts
index b07aacf443abb96..5a5cce6ec23b621 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/generate_breadcrumbs.test.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/generate_breadcrumbs.test.ts
@@ -7,7 +7,8 @@
 import { generateBreadcrumb } from './generate_breadcrumbs';
 import { appSearchBreadcrumbs, enterpriseSearchBreadcrumbs } from './';
 
-import { mockHistory } from '../../__mocks__';
+import { mockHistory as mockHistoryUntyped } from '../../__mocks__';
+const mockHistory = mockHistoryUntyped as any;
 
 jest.mock('../react_router_helpers', () => ({ letBrowserHandleEvent: jest.fn(() => false) }));
 import { letBrowserHandleEvent } from '../react_router_helpers';
@@ -31,7 +32,7 @@ describe('generateBreadcrumb', () => {
   });
 
   it('prevents default navigation and uses React Router history on click', () => {
-    const breadcrumb = generateBreadcrumb({ text: '', path: '/', history: mockHistory });
+    const breadcrumb = generateBreadcrumb({ text: '', path: '/', history: mockHistory }) as any;
     const event = { preventDefault: jest.fn() };
     breadcrumb.onClick(event);
 
@@ -40,9 +41,9 @@ describe('generateBreadcrumb', () => {
   });
 
   it('does not prevents default browser behavior on new tab/window clicks', () => {
-    const breadcrumb = generateBreadcrumb({ text: '', path: '/', history: mockHistory });
+    const breadcrumb = generateBreadcrumb({ text: '', path: '/', history: mockHistory }) as any;
 
-    letBrowserHandleEvent.mockImplementationOnce(() => true);
+    (letBrowserHandleEvent as jest.Mock).mockImplementationOnce(() => true);
     breadcrumb.onClick();
 
     expect(mockHistory.push).not.toHaveBeenCalled();
@@ -103,19 +104,19 @@ describe('enterpriseSearchBreadcrumbs', () => {
   describe('links', () => {
     const eventMock = {
       preventDefault: jest.fn(),
-    };
+    } as any;
 
     it('has Enterprise Search text first', () => {
       expect(subject()[0].onClick).toBeUndefined();
     });
 
     it('has a link to page 1 second', () => {
-      subject()[1].onClick(eventMock);
+      (subject()[1] as any).onClick(eventMock);
       expect(mockHistory.push).toHaveBeenCalledWith('/page1');
     });
 
     it('has a link to page 2 last', () => {
-      subject()[2].onClick(eventMock);
+      (subject()[2] as any).onClick(eventMock);
       expect(mockHistory.push).toHaveBeenCalledWith('/page2');
     });
   });
@@ -136,7 +137,7 @@ describe('appSearchBreadcrumbs', () => {
   beforeEach(() => {
     jest.clearAllMocks();
     mockHistory.createHref.mockImplementation(
-      ({ pathname }) => `/enterprise_search/app_search${pathname}`
+      ({ pathname }: any) => `/enterprise_search/app_search${pathname}`
     );
   });
 
@@ -181,24 +182,24 @@ describe('appSearchBreadcrumbs', () => {
   describe('links', () => {
     const eventMock = {
       preventDefault: jest.fn(),
-    };
+    } as any;
 
     it('has Enterprise Search text first', () => {
       expect(subject()[0].onClick).toBeUndefined();
     });
 
     it('has a link to App Search second', () => {
-      subject()[1].onClick(eventMock);
+      (subject()[1] as any).onClick(eventMock);
       expect(mockHistory.push).toHaveBeenCalledWith('/');
     });
 
     it('has a link to page 1 third', () => {
-      subject()[2].onClick(eventMock);
+      (subject()[2] as any).onClick(eventMock);
       expect(mockHistory.push).toHaveBeenCalledWith('/page1');
     });
 
     it('has a link to page 2 last', () => {
-      subject()[3].onClick(eventMock);
+      (subject()[3] as any).onClick(eventMock);
       expect(mockHistory.push).toHaveBeenCalledWith('/page2');
     });
   });
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/generate_breadcrumbs.ts b/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/generate_breadcrumbs.ts
index 659a113dc31dec0..0e1bb796cbf2eca 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/generate_breadcrumbs.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/generate_breadcrumbs.ts
@@ -21,7 +21,7 @@ interface IGenerateBreadcrumbProps {
 }
 
 export const generateBreadcrumb = ({ text, path, history }: IGenerateBreadcrumbProps) => {
-  const breadcrumb = { text };
+  const breadcrumb = { text } as EuiBreadcrumb;
 
   if (path && history) {
     breadcrumb.href = history.createHref({ pathname: path });
@@ -39,13 +39,15 @@ export const generateBreadcrumb = ({ text, path, history }: IGenerateBreadcrumbP
  * Product-specific breadcrumb helpers
  */
 
-type TBreadcrumbs = EuiBreadcrumb[] | [];
+export type TBreadcrumbs = IGenerateBreadcrumbProps[];
 
 export const enterpriseSearchBreadcrumbs = (history: History) => (
   breadcrumbs: TBreadcrumbs = []
 ) => [
   generateBreadcrumb({ text: 'Enterprise Search' }),
-  ...breadcrumbs.map(({ text, path }) => generateBreadcrumb({ text, path, history })),
+  ...breadcrumbs.map(({ text, path }: IGenerateBreadcrumbProps) =>
+    generateBreadcrumb({ text, path, history })
+  ),
 ];
 
 export const appSearchBreadcrumbs = (history: History) => (breadcrumbs: TBreadcrumbs = []) =>
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/set_breadcrumbs.test.tsx b/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/set_breadcrumbs.test.tsx
index aeaa38a5ad38f44..974ca54277c51c9 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/set_breadcrumbs.test.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/set_breadcrumbs.test.tsx
@@ -14,16 +14,16 @@ import { appSearchBreadcrumbs, SetAppSearchBreadcrumbs } from './';
 
 describe('SetAppSearchBreadcrumbs', () => {
   const setBreadcrumbs = jest.fn();
-  const builtBreadcrumbs = [];
+  const builtBreadcrumbs = [] as any;
   const appSearchBreadCrumbsInnerCall = jest.fn().mockReturnValue(builtBreadcrumbs);
   const appSearchBreadCrumbsOuterCall = jest.fn().mockReturnValue(appSearchBreadCrumbsInnerCall);
-  appSearchBreadcrumbs.mockImplementation(appSearchBreadCrumbsOuterCall);
+  (appSearchBreadcrumbs as jest.Mock).mockImplementation(appSearchBreadCrumbsOuterCall);
 
   afterEach(() => {
     jest.clearAllMocks();
   });
 
-  const mountSetAppSearchBreadcrumbs = (props) => {
+  const mountSetAppSearchBreadcrumbs = (props: any) => {
     return mountWithKibanaContext(<SetAppSearchBreadcrumbs {...props} />, {
       http: {},
       enterpriseSearchUrl: 'http://localhost:3002',
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/set_breadcrumbs.tsx b/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/set_breadcrumbs.tsx
index aaa54febcc20b03..ad3cd65c09516bf 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/set_breadcrumbs.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/kibana_breadcrumbs/set_breadcrumbs.tsx
@@ -8,7 +8,7 @@ import React, { useContext, useEffect } from 'react';
 import { useHistory } from 'react-router-dom';
 import { Breadcrumb as EuiBreadcrumb } from '@elastic/eui';
 import { KibanaContext, IKibanaContext } from '../../index';
-import { appSearchBreadcrumbs } from './generate_breadcrumbs';
+import { appSearchBreadcrumbs, TBreadcrumbs } from './generate_breadcrumbs';
 
 /**
  * Small on-mount helper for setting Kibana's chrome breadcrumbs on any App Search view
@@ -17,20 +17,27 @@ import { appSearchBreadcrumbs } from './generate_breadcrumbs';
 
 export type TSetBreadcrumbs = (breadcrumbs: EuiBreadcrumb[]) => void;
 
-interface ISetBreadcrumbsProps {
+interface IBreadcrumbProps {
   text: string;
-  isRoot?: boolean;
+  isRoot?: never;
+}
+interface IRootBreadcrumbProps {
+  isRoot: true;
+  text?: never;
 }
 
-export const SetAppSearchBreadcrumbs: React.FC<ISetBreadcrumbsProps> = ({ text, isRoot }) => {
+export const SetAppSearchBreadcrumbs: React.FC<IBreadcrumbProps | IRootBreadcrumbProps> = ({
+  text,
+  isRoot,
+}) => {
   const history = useHistory();
   const { setBreadcrumbs } = useContext(KibanaContext) as IKibanaContext;
 
   const crumb = isRoot ? [] : [{ text, path: history.location.pathname }];
 
   useEffect(() => {
-    setBreadcrumbs(appSearchBreadcrumbs(history)(crumb));
-  }, []); // eslint-disable-line react-hooks/exhaustive-deps
+    setBreadcrumbs(appSearchBreadcrumbs(history)(crumb as TBreadcrumbs | []));
+  }, []);
 
   return null;
 };
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_checks.test.ts b/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_checks.test.ts
index e21bf004b39a2dd..ad134e7d36b10c5 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_checks.test.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_checks.test.ts
@@ -8,26 +8,26 @@ import { hasPlatinumLicense } from './license_checks';
 
 describe('hasPlatinumLicense', () => {
   it('is true for platinum licenses', () => {
-    expect(hasPlatinumLicense({ isActive: true, type: 'platinum' })).toEqual(true);
+    expect(hasPlatinumLicense({ isActive: true, type: 'platinum' } as any)).toEqual(true);
   });
 
   it('is true for enterprise licenses', () => {
-    expect(hasPlatinumLicense({ isActive: true, type: 'enterprise' })).toEqual(true);
+    expect(hasPlatinumLicense({ isActive: true, type: 'enterprise' } as any)).toEqual(true);
   });
 
   it('is true for trial licenses', () => {
-    expect(hasPlatinumLicense({ isActive: true, type: 'platinum' })).toEqual(true);
+    expect(hasPlatinumLicense({ isActive: true, type: 'platinum' } as any)).toEqual(true);
   });
 
   it('is false if the current license is expired', () => {
-    expect(hasPlatinumLicense({ isActive: false, type: 'platinum' })).toEqual(false);
-    expect(hasPlatinumLicense({ isActive: false, type: 'enterprise' })).toEqual(false);
-    expect(hasPlatinumLicense({ isActive: false, type: 'trial' })).toEqual(false);
+    expect(hasPlatinumLicense({ isActive: false, type: 'platinum' } as any)).toEqual(false);
+    expect(hasPlatinumLicense({ isActive: false, type: 'enterprise' } as any)).toEqual(false);
+    expect(hasPlatinumLicense({ isActive: false, type: 'trial' } as any)).toEqual(false);
   });
 
   it('is false for licenses below platinum', () => {
-    expect(hasPlatinumLicense({ isActive: true, type: 'basic' })).toEqual(false);
-    expect(hasPlatinumLicense({ isActive: false, type: 'standard' })).toEqual(false);
-    expect(hasPlatinumLicense({ isActive: true, type: 'gold' })).toEqual(false);
+    expect(hasPlatinumLicense({ isActive: true, type: 'basic' } as any)).toEqual(false);
+    expect(hasPlatinumLicense({ isActive: false, type: 'standard' } as any)).toEqual(false);
+    expect(hasPlatinumLicense({ isActive: true, type: 'gold' } as any)).toEqual(false);
   });
 });
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_checks.ts b/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_checks.ts
index 7d0de8a093b3175..363ae39ab0da4ca 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_checks.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_checks.ts
@@ -4,8 +4,8 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import { ILicense } from '../../../../../../licensing/public';
+import { ILicense } from '../../../../../licensing/public';
 
-export const hasPlatinumLicense = (license: ILicenseContext) => {
-  return license?.isActive && ['platinum', 'enterprise', 'trial'].includes(license?.type);
+export const hasPlatinumLicense = (license: ILicense) => {
+  return license?.isActive && ['platinum', 'enterprise', 'trial'].includes(license?.type as string);
 };
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_context.test.tsx b/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_context.test.tsx
index 01d976bf49c197e..c65474ec1f5900a 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_context.test.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_context.test.tsx
@@ -10,9 +10,9 @@ import { mountWithContext } from '../../__mocks__';
 import { LicenseContext, ILicenseContext } from './';
 
 describe('LicenseProvider', () => {
-  const MockComponent: React.FC<> = () => {
+  const MockComponent: React.FC = () => {
     const { license } = useContext(LicenseContext) as ILicenseContext;
-    return <div className="license-test">{license.type}</div>;
+    return <div className="license-test">{license?.type}</div>;
   };
 
   it('renders children', () => {
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_context.tsx b/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_context.tsx
index c8295196aedb57c..dec9cdac892f620 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_context.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/licensing/license_context.tsx
@@ -9,15 +9,15 @@ import useObservable from 'react-use/lib/useObservable';
 
 import { KibanaContext, IKibanaContext } from '../../';
 
-import { ILicense } from '../../../../licensing/public';
+import { ILicense } from '../../../../../licensing/public';
 
 export interface ILicenseContext {
-  license?: ILicense;
+  license: ILicense;
 }
 
-export const LicenseContext = React.createContext();
+export const LicenseContext = React.createContext({});
 
-export const LicenseProvider: React.FC<> = ({ children }) => {
+export const LicenseProvider: React.FC = ({ children }) => {
   // Listen for changes to license subscription
   const { license$ } = useContext(KibanaContext) as IKibanaContext;
   const license = useObservable(license$);
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/eui_link.test.tsx b/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/eui_link.test.tsx
index eb9b9f3e35e0619..7d4c068b211555d 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/eui_link.test.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/eui_link.test.tsx
@@ -5,7 +5,7 @@
  */
 
 import React from 'react';
-import { shallow } from 'enzyme';
+import { shallow, mount } from 'enzyme';
 import { EuiLink, EuiButton } from '@elastic/eui';
 
 import '../../__mocks__/react_router_history.mock';
@@ -25,23 +25,21 @@ describe('EUI & React Router Component Helpers', () => {
   });
 
   it('renders an EuiButton', () => {
-    const wrapper = shallow(<EuiReactRouterButton to="/" />)
-      .find(EuiReactRouterLink)
-      .dive();
+    const wrapper = shallow(<EuiReactRouterButton to="/" />);
 
     expect(wrapper.find(EuiButton)).toHaveLength(1);
   });
 
   it('passes down all ...rest props', () => {
-    const wrapper = shallow(<EuiReactRouterLink to="/" data-test-subj="foo" disabled={true} />);
+    const wrapper = shallow(<EuiReactRouterLink to="/" data-test-subj="foo" external={true} />);
     const link = wrapper.find(EuiLink);
 
-    expect(link.prop('disabled')).toEqual(true);
+    expect(link.prop('external')).toEqual(true);
     expect(link.prop('data-test-subj')).toEqual('foo');
   });
 
   it('renders with the correct href and onClick props', () => {
-    const wrapper = shallow(<EuiReactRouterLink to="/foo/bar" />);
+    const wrapper = mount(<EuiReactRouterLink to="/foo/bar" />);
     const link = wrapper.find(EuiLink);
 
     expect(link.prop('onClick')).toBeInstanceOf(Function);
@@ -51,7 +49,7 @@ describe('EUI & React Router Component Helpers', () => {
 
   describe('onClick', () => {
     it('prevents default navigation and uses React Router history', () => {
-      const wrapper = shallow(<EuiReactRouterLink to="/bar/baz" />);
+      const wrapper = mount(<EuiReactRouterLink to="/bar/baz" />);
 
       const simulatedEvent = {
         button: 0,
@@ -65,7 +63,7 @@ describe('EUI & React Router Component Helpers', () => {
     });
 
     it('does not prevent default browser behavior on new tab/window clicks', () => {
-      const wrapper = shallow(<EuiReactRouterLink to="/bar/baz" />);
+      const wrapper = mount(<EuiReactRouterLink to="/bar/baz" />);
 
       const simulatedEvent = {
         shiftKey: true,
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/eui_link.tsx b/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/eui_link.tsx
index 3c410584cc49d3b..f486e432bae76ab 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/eui_link.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/eui_link.tsx
@@ -6,7 +6,7 @@
 
 import React from 'react';
 import { useHistory } from 'react-router-dom';
-import { EuiLink, EuiButton } from '@elastic/eui';
+import { EuiLink, EuiButton, EuiButtonProps, EuiLinkAnchorProps } from '@elastic/eui';
 
 import { letBrowserHandleEvent } from './link_events';
 
@@ -19,13 +19,12 @@ import { letBrowserHandleEvent } from './link_events';
 
 interface IEuiReactRouterProps {
   to: string;
-  isButton?: boolean;
 }
 
-export const EuiReactRouterLink: React.FC<IEuiReactRouterProps> = ({ to, isButton, ...rest }) => {
+export const EuiReactRouterHelper: React.FC<IEuiReactRouterProps> = ({ to, children }) => {
   const history = useHistory();
 
-  const onClick = (event) => {
+  const onClick = (event: React.MouseEvent) => {
     if (letBrowserHandleEvent(event)) return;
 
     // Prevent regular link behavior, which causes a browser refresh.
@@ -38,10 +37,21 @@ export const EuiReactRouterLink: React.FC<IEuiReactRouterProps> = ({ to, isButto
   // Generate the correct link href (with basename etc. accounted for)
   const href = history.createHref({ pathname: to });
 
-  const props = { ...rest, href, onClick };
-  return isButton ? <EuiButton {...props} /> : <EuiLink {...props} />;
+  const reactRouterProps = { href, onClick };
+  return React.cloneElement(children as React.ReactElement, reactRouterProps);
 };
 
-export const EuiReactRouterButton: React.FC<IEuiReactRouterProps> = (props) => (
-  <EuiReactRouterLink {...props} isButton />
+type TEuiReactRouterLinkProps = EuiLinkAnchorProps & IEuiReactRouterProps;
+type TEuiReactRouterButtonProps = EuiButtonProps & IEuiReactRouterProps;
+
+export const EuiReactRouterLink: React.FC<TEuiReactRouterLinkProps> = ({ to, ...rest }) => (
+  <EuiReactRouterHelper to={to}>
+    <EuiLink {...rest} />
+  </EuiReactRouterHelper>
+);
+
+export const EuiReactRouterButton: React.FC<TEuiReactRouterButtonProps> = ({ to, ...rest }) => (
+  <EuiReactRouterHelper to={to}>
+    <EuiButton {...rest} />
+  </EuiReactRouterHelper>
 );
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/link_events.test.ts b/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/link_events.test.ts
index 0845e5562776b4f..3682946b63a1369 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/link_events.test.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/link_events.test.ts
@@ -17,7 +17,7 @@ describe('letBrowserHandleEvent', () => {
     target: {
       getAttribute: () => '_self',
     },
-  };
+  } as any;
 
   describe('the browser should handle the link when', () => {
     it('default is prevented', () => {
@@ -95,7 +95,7 @@ describe('letBrowserHandleEvent', () => {
   });
 });
 
-const targetValue = (value) => {
+const targetValue = (value: string | null) => {
   return {
     getAttribute: () => value,
   };
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/link_events.ts b/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/link_events.ts
index 67e987623c2c173..93da2ab71d9527f 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/link_events.ts
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/react_router_helpers/link_events.ts
@@ -4,14 +4,14 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import { SyntheticEvent } from 'react';
+import { MouseEvent } from 'react';
 
 /**
  * Helper functions for determining which events we should
  * let browsers handle natively, e.g. new tabs/windows
  */
 
-type THandleEvent = (event: SyntheticEvent) => boolean;
+type THandleEvent = (event: MouseEvent) => boolean;
 
 export const letBrowserHandleEvent: THandleEvent = (event) =>
   event.defaultPrevented ||
@@ -25,6 +25,7 @@ const isModifiedEvent: THandleEvent = (event) =>
 const isLeftClickEvent: THandleEvent = (event) => event.button === 0;
 
 const isTargetBlank: THandleEvent = (event) => {
-  const target = event.target.getAttribute('target');
+  const element = event.target as HTMLElement;
+  const target = element.getAttribute('target');
   return !!target && target !== '_self';
 };
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/telemetry/send_telemetry.test.tsx b/x-pack/plugins/enterprise_search/public/applications/shared/telemetry/send_telemetry.test.tsx
index 7f4a0d3f19074bb..341c7100cb062a9 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/telemetry/send_telemetry.test.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/telemetry/send_telemetry.test.tsx
@@ -33,18 +33,19 @@ describe('Shared Telemetry Helpers', () => {
     });
 
     it('throws an error if the telemetry endpoint fails', () => {
-      const httpRejectMock = { put: () => Promise.reject() };
+      const httpRejectMock = sendTelemetry({
+        http: { put: () => Promise.reject() },
+      } as any);
 
-      expect(sendTelemetry({ http: httpRejectMock })).rejects.toThrow('Unable to send telemetry');
+      expect(httpRejectMock).rejects.toThrow('Unable to send telemetry');
     });
   });
 
   describe('React component helpers', () => {
     it('SendAppSearchTelemetry component', () => {
-      const wrapper = mountWithKibanaContext(
-        <SendAppSearchTelemetry action="clicked" metric="button" />,
-        { http: httpMock }
-      );
+      mountWithKibanaContext(<SendAppSearchTelemetry action="clicked" metric="button" />, {
+        http: httpMock,
+      });
 
       expect(httpMock.put).toHaveBeenCalledWith('/api/app_search/telemetry', {
         headers: { 'content-type': 'application/json' },
diff --git a/x-pack/plugins/enterprise_search/public/applications/shared/telemetry/send_telemetry.tsx b/x-pack/plugins/enterprise_search/public/applications/shared/telemetry/send_telemetry.tsx
index 33ef0d7d14b95cd..6797cde1f14b45e 100644
--- a/x-pack/plugins/enterprise_search/public/applications/shared/telemetry/send_telemetry.tsx
+++ b/x-pack/plugins/enterprise_search/public/applications/shared/telemetry/send_telemetry.tsx
@@ -6,7 +6,7 @@
 
 import React, { useContext, useEffect } from 'react';
 
-import { HttpHandler } from 'src/core/public';
+import { HttpSetup } from 'src/core/public';
 import { KibanaContext, IKibanaContext } from '../../index';
 
 interface ISendTelemetryProps {
@@ -15,7 +15,7 @@ interface ISendTelemetryProps {
 }
 
 interface ISendTelemetry extends ISendTelemetryProps {
-  http(): HttpHandler;
+  http: HttpSetup;
   product: 'app_search' | 'workplace_search' | 'enterprise_search';
 }
 
diff --git a/x-pack/plugins/enterprise_search/public/plugin.ts b/x-pack/plugins/enterprise_search/public/plugin.ts
index 5863df5ccba25dd..1ebfdd779a791d7 100644
--- a/x-pack/plugins/enterprise_search/public/plugin.ts
+++ b/x-pack/plugins/enterprise_search/public/plugin.ts
@@ -32,7 +32,7 @@ export interface PluginsSetup {
 export class EnterpriseSearchPlugin implements Plugin {
   private config: ClientConfigType;
 
-  constructor(private readonly initializerContext: PluginInitializerContext) {
+  constructor(initializerContext: PluginInitializerContext) {
     this.config = initializerContext.config.get<ClientConfigType>();
   }
 
diff --git a/x-pack/plugins/enterprise_search/server/collectors/app_search/telemetry.test.ts b/x-pack/plugins/enterprise_search/server/collectors/app_search/telemetry.test.ts
index 4be2c220024bc14..9e82a7f8da9ee8a 100644
--- a/x-pack/plugins/enterprise_search/server/collectors/app_search/telemetry.test.ts
+++ b/x-pack/plugins/enterprise_search/server/collectors/app_search/telemetry.test.ts
@@ -17,7 +17,7 @@ describe('App Search Telemetry Usage Collector', () => {
   const usageCollectionMock = {
     makeUsageCollector: makeUsageCollectorStub,
     registerCollector: registerStub,
-  };
+  } as any;
 
   const savedObjectsRepoStub = {
     get: () => ({
@@ -35,7 +35,7 @@ describe('App Search Telemetry Usage Collector', () => {
   };
   const savedObjectsMock = {
     createInternalRepository: jest.fn(() => savedObjectsRepoStub),
-  };
+  } as any;
 
   beforeEach(() => {
     jest.clearAllMocks();
@@ -48,6 +48,7 @@ describe('App Search Telemetry Usage Collector', () => {
       expect(registerStub).toHaveBeenCalledTimes(1);
       expect(makeUsageCollectorStub).toHaveBeenCalledTimes(1);
       expect(makeUsageCollectorStub.mock.calls[0][0].type).toBe('app_search');
+      expect(makeUsageCollectorStub.mock.calls[0][0].isReady()).toBe(true);
     });
   });
 
@@ -74,7 +75,7 @@ describe('App Search Telemetry Usage Collector', () => {
     });
 
     it('should not error & should return a default telemetry object if no saved data exists', async () => {
-      const emptySavedObjectsMock = { createInternalRepository: () => ({}) };
+      const emptySavedObjectsMock = { createInternalRepository: () => ({}) } as any;
 
       registerTelemetryUsageCollector(usageCollectionMock, emptySavedObjectsMock);
       const savedObjectsCounts = await makeUsageCollectorStub.mock.calls[0][0].fetch();
diff --git a/x-pack/plugins/enterprise_search/server/collectors/app_search/telemetry.ts b/x-pack/plugins/enterprise_search/server/collectors/app_search/telemetry.ts
index 12b5a165bf1ac75..2a396ead2f7188f 100644
--- a/x-pack/plugins/enterprise_search/server/collectors/app_search/telemetry.ts
+++ b/x-pack/plugins/enterprise_search/server/collectors/app_search/telemetry.ts
@@ -5,7 +5,11 @@
  */
 
 import { set } from 'lodash';
-import { ISavedObjectsRepository, SavedObjectsServiceStart } from 'src/core/server';
+import {
+  ISavedObjectsRepository,
+  SavedObjectsServiceStart,
+  SavedObjectAttributes,
+} from 'src/core/server';
 import { UsageCollectionSetup } from 'src/plugins/usage_collection/server';
 
 import { AS_TELEMETRY_NAME, ITelemetrySavedObject } from '../../saved_objects/app_search/telemetry';
@@ -21,6 +25,7 @@ export const registerTelemetryUsageCollector = (
   const telemetryUsageCollector = usageCollection.makeUsageCollector({
     type: 'app_search',
     fetch: async () => fetchTelemetryMetrics(savedObjects),
+    isReady: () => true,
   });
   usageCollection.registerCollector(telemetryUsageCollector);
 };
@@ -31,7 +36,9 @@ export const registerTelemetryUsageCollector = (
 
 const fetchTelemetryMetrics = async (savedObjects: SavedObjectsServiceStart) => {
   const savedObjectsRepository = savedObjects.createInternalRepository();
-  const savedObjectAttributes = await getSavedObjectAttributesFromRepo(savedObjectsRepository);
+  const savedObjectAttributes = (await getSavedObjectAttributesFromRepo(
+    savedObjectsRepository
+  )) as SavedObjectAttributes;
 
   const defaultTelemetrySavedObject: ITelemetrySavedObject = {
     ui_viewed: {
@@ -68,10 +75,6 @@ const fetchTelemetryMetrics = async (savedObjects: SavedObjectsServiceStart) =>
  * Helper function - fetches saved objects attributes
  */
 
-interface ISavedObjectAttributes {
-  [key: string]: any;
-}
-
 const getSavedObjectAttributesFromRepo = async (
   savedObjectsRepository: ISavedObjectsRepository
 ) => {
diff --git a/x-pack/plugins/enterprise_search/server/plugin.ts b/x-pack/plugins/enterprise_search/server/plugin.ts
index 077d900a8d8cfb9..a8430ad8f56af5b 100644
--- a/x-pack/plugins/enterprise_search/server/plugin.ts
+++ b/x-pack/plugins/enterprise_search/server/plugin.ts
@@ -12,6 +12,7 @@ import {
   CoreSetup,
   Logger,
   SavedObjectsServiceStart,
+  IRouter,
 } from 'src/core/server';
 import { UsageCollectionSetup } from 'src/plugins/usage_collection/server';
 
@@ -28,10 +29,16 @@ export interface ServerConfigType {
   host?: string;
 }
 
+export interface IRouteDependencies {
+  router: IRouter;
+  config: ServerConfigType;
+  log: Logger;
+  getSavedObjectsService?(): SavedObjectsServiceStart;
+}
+
 export class EnterpriseSearchPlugin implements Plugin {
   private config: Observable<ServerConfigType>;
   private logger: Logger;
-  private savedObjects?: SavedObjectsServiceStart;
 
   constructor(initializerContext: PluginInitializerContext) {
     this.config = initializerContext.config.create<ServerConfigType>();
diff --git a/x-pack/plugins/enterprise_search/server/routes/__mocks__/router.mock.ts b/x-pack/plugins/enterprise_search/server/routes/__mocks__/router.mock.ts
index 1cec5da0551405d..332d1ad1062f20b 100644
--- a/x-pack/plugins/enterprise_search/server/routes/__mocks__/router.mock.ts
+++ b/x-pack/plugins/enterprise_search/server/routes/__mocks__/router.mock.ts
@@ -5,7 +5,12 @@
  */
 
 import { httpServiceMock, httpServerMock } from 'src/core/server/mocks';
-import { IRouter, RequestHandlerContext, RouteValidatorConfig } from 'src/core/server';
+import {
+  IRouter,
+  KibanaRequest,
+  RequestHandlerContext,
+  RouteValidatorConfig,
+} from 'src/core/server';
 
 /**
  * Test helper that mocks Kibana's router and DRYs out various helper (callRoute, schema validation)
@@ -14,13 +19,24 @@ import { IRouter, RequestHandlerContext, RouteValidatorConfig } from 'src/core/s
 type methodType = 'get' | 'post' | 'put' | 'patch' | 'delete';
 type payloadType = 'params' | 'query' | 'body';
 
+interface IMockRouterProps {
+  method: methodType;
+  payload: payloadType;
+}
+interface IMockRouterRequest {
+  body?: object;
+  query?: object;
+  params?: object;
+}
+type TMockRouterRequest = KibanaRequest | IMockRouterRequest;
+
 export class MockRouter {
-  public router: jest.Mocked<IRouter>;
+  public router!: jest.Mocked<IRouter>;
   public method: methodType;
   public payload: payloadType;
   public response = httpServerMock.createResponseFactory();
 
-  private constructor({ method, payload }) {
+  constructor({ method, payload }: IMockRouterProps) {
     this.createRouter();
     this.method = method;
     this.payload = payload;
@@ -30,29 +46,32 @@ export class MockRouter {
     this.router = httpServiceMock.createRouter();
   };
 
-  public callRoute = async (request) => {
-    const [_, handler] = this.router[this.method].mock.calls[0];
+  public callRoute = async (request: TMockRouterRequest) => {
+    const [, handler] = this.router[this.method].mock.calls[0];
 
     const context = {} as jest.Mocked<RequestHandlerContext>;
-    await handler(context, httpServerMock.createKibanaRequest(request), this.response);
+    await handler(context, httpServerMock.createKibanaRequest(request as any), this.response);
   };
 
   /**
    * Schema validation helpers
    */
 
-  public validateRoute = (request) => {
+  public validateRoute = (request: TMockRouterRequest) => {
     const [config] = this.router[this.method].mock.calls[0];
     const validate = config.validate as RouteValidatorConfig<{}, {}, {}>;
 
-    validate[this.payload].validate(request[this.payload]);
+    const payloadValidation = validate[this.payload] as { validate(request: KibanaRequest): void };
+    const payloadRequest = request[this.payload] as KibanaRequest;
+
+    payloadValidation.validate(payloadRequest);
   };
 
-  public shouldValidate = (request) => {
+  public shouldValidate = (request: TMockRouterRequest) => {
     expect(() => this.validateRoute(request)).not.toThrow();
   };
 
-  public shouldThrow = (request) => {
+  public shouldThrow = (request: TMockRouterRequest) => {
     expect(() => this.validateRoute(request)).toThrow();
   };
 }
diff --git a/x-pack/plugins/enterprise_search/server/routes/app_search/engines.test.ts b/x-pack/plugins/enterprise_search/server/routes/app_search/engines.test.ts
index 722ad0d9269d332..7eab94940f0d14f 100644
--- a/x-pack/plugins/enterprise_search/server/routes/app_search/engines.test.ts
+++ b/x-pack/plugins/enterprise_search/server/routes/app_search/engines.test.ts
@@ -172,7 +172,7 @@ describe('engine routes', () => {
               return Promise.resolve(new Response(JSON.stringify(response)));
             });
           },
-          andReturnInvalidData(response: object) {
+          andReturnInvalidData() {
             fetchMock.mockImplementation((url: string, params: object) => {
               expect(url).toEqual(expectedUrl);
               expect(params).toEqual(expectedParams);
@@ -180,7 +180,7 @@ describe('engine routes', () => {
               return Promise.resolve(new Response(JSON.stringify({ foo: 'bar' })));
             });
           },
-          andReturnError(response: object) {
+          andReturnError() {
             fetchMock.mockImplementation((url: string, params: object) => {
               expect(url).toEqual(expectedUrl);
               expect(params).toEqual(expectedParams);
diff --git a/x-pack/plugins/enterprise_search/server/routes/app_search/engines.ts b/x-pack/plugins/enterprise_search/server/routes/app_search/engines.ts
index ebe2252b24eefdb..ffc7a0228454ff0 100644
--- a/x-pack/plugins/enterprise_search/server/routes/app_search/engines.ts
+++ b/x-pack/plugins/enterprise_search/server/routes/app_search/engines.ts
@@ -8,9 +8,10 @@ import fetch from 'node-fetch';
 import querystring from 'querystring';
 import { schema } from '@kbn/config-schema';
 
+import { IRouteDependencies } from '../../plugin';
 import { ENGINES_PAGE_SIZE } from '../../../common/constants';
 
-export function registerEnginesRoute({ router, config, log }) {
+export function registerEnginesRoute({ router, config, log }: IRouteDependencies) {
   router.get(
     {
       path: '/api/app_search/engines',
@@ -23,7 +24,7 @@ export function registerEnginesRoute({ router, config, log }) {
     },
     async (context, request, response) => {
       try {
-        const appSearchUrl = config.host;
+        const appSearchUrl = config.host as string;
         const { type, pageIndex } = request.query;
 
         const params = querystring.stringify({
@@ -34,7 +35,7 @@ export function registerEnginesRoute({ router, config, log }) {
         const url = `${encodeURI(appSearchUrl)}/as/engines/collection?${params}`;
 
         const enginesResponse = await fetch(url, {
-          headers: { Authorization: request.headers.authorization },
+          headers: { Authorization: request.headers.authorization as string },
         });
 
         if (enginesResponse.url.endsWith('/login')) {
@@ -58,7 +59,7 @@ export function registerEnginesRoute({ router, config, log }) {
         }
       } catch (e) {
         log.error(`Cannot connect to App Search: ${e.toString()}`);
-        if (e instanceof Error) log.debug(e.stack);
+        if (e instanceof Error) log.debug(e.stack as string);
 
         return response.notFound({ body: 'cannot-connect' });
       }
diff --git a/x-pack/plugins/enterprise_search/server/routes/app_search/telemetry.test.ts b/x-pack/plugins/enterprise_search/server/routes/app_search/telemetry.test.ts
index 7644f3019de8060..a676c68d897b5a0 100644
--- a/x-pack/plugins/enterprise_search/server/routes/app_search/telemetry.test.ts
+++ b/x-pack/plugins/enterprise_search/server/routes/app_search/telemetry.test.ts
@@ -26,13 +26,13 @@ describe('App Search Telemetry API', () => {
       router: mockRouter.router,
       getSavedObjectsService: () => savedObjectsServiceMock.create(),
       log: mockLogger,
-    });
+    } as any);
   });
 
   describe('PUT /api/app_search/telemetry', () => {
     it('increments the saved objects counter', async () => {
       const successResponse = { success: true };
-      incrementUICounter.mockImplementation(jest.fn(() => successResponse));
+      (incrementUICounter as jest.Mock).mockImplementation(jest.fn(() => successResponse));
 
       await mockRouter.callRoute({ body: { action: 'viewed', metric: 'setup_guide' } });
 
@@ -45,7 +45,7 @@ describe('App Search Telemetry API', () => {
     });
 
     it('throws an error when incrementing fails', async () => {
-      incrementUICounter.mockImplementation(jest.fn(() => Promise.reject('Failed')));
+      (incrementUICounter as jest.Mock).mockImplementation(jest.fn(() => Promise.reject('Failed')));
 
       await mockRouter.callRoute({ body: { action: 'error', metric: 'error' } });
 
@@ -54,6 +54,20 @@ describe('App Search Telemetry API', () => {
       expect(mockRouter.response.internalError).toHaveBeenCalled();
     });
 
+    it('throws an error if the Saved Objects service is unavailable', async () => {
+      jest.clearAllMocks();
+      registerTelemetryRoute({
+        router: mockRouter.router,
+        getSavedObjectsService: null,
+        log: mockLogger,
+      } as any);
+      await mockRouter.callRoute({});
+
+      expect(incrementUICounter).not.toHaveBeenCalled();
+      expect(mockLogger.error).toHaveBeenCalled();
+      expect(mockRouter.response.internalError).toHaveBeenCalled();
+    });
+
     describe('validates', () => {
       it('correctly', () => {
         const request = { body: { action: 'viewed', metric: 'setup_guide' } };
diff --git a/x-pack/plugins/enterprise_search/server/routes/app_search/telemetry.ts b/x-pack/plugins/enterprise_search/server/routes/app_search/telemetry.ts
index 6b7657a384e9f10..4cc9b64adc0927a 100644
--- a/x-pack/plugins/enterprise_search/server/routes/app_search/telemetry.ts
+++ b/x-pack/plugins/enterprise_search/server/routes/app_search/telemetry.ts
@@ -6,9 +6,14 @@
 
 import { schema } from '@kbn/config-schema';
 
+import { IRouteDependencies } from '../../plugin';
 import { incrementUICounter } from '../../collectors/app_search/telemetry';
 
-export function registerTelemetryRoute({ router, getSavedObjectsService, log }) {
+export function registerTelemetryRoute({
+  router,
+  getSavedObjectsService,
+  log,
+}: IRouteDependencies) {
   router.put(
     {
       path: '/api/app_search/telemetry',
@@ -27,6 +32,8 @@ export function registerTelemetryRoute({ router, getSavedObjectsService, log })
       const { action, metric } = request.body;
 
       try {
+        if (!getSavedObjectsService) throw new Error('Could not find Saved Objects service');
+
         return response.ok({
           body: await incrementUICounter({
             savedObjects: getSavedObjectsService(),
diff --git a/x-pack/plugins/enterprise_search/server/saved_objects/app_search/telemetry.ts b/x-pack/plugins/enterprise_search/server/saved_objects/app_search/telemetry.ts
index 20c03b6aece8a3c..02bfe450ce7eb4f 100644
--- a/x-pack/plugins/enterprise_search/server/saved_objects/app_search/telemetry.ts
+++ b/x-pack/plugins/enterprise_search/server/saved_objects/app_search/telemetry.ts
@@ -27,7 +27,7 @@ export interface ITelemetrySavedObject {
 export const appSearchTelemetryType: SavedObjectsType = {
   name: AS_TELEMETRY_NAME,
   hidden: false,
-  namespaceAgnostic: true,
+  namespaceType: 'single',
   mappings: {
     properties: {
       ui_viewed: {