diff --git a/plugins/woocommerce-admin/bin/packages/build.js b/plugins/woocommerce-admin/bin/packages/build.js
index b3a9a206127..9636dfebef1 100755
--- a/plugins/woocommerce-admin/bin/packages/build.js
+++ b/plugins/woocommerce-admin/bin/packages/build.js
@@ -63,10 +63,12 @@ const isScssFile = ( filepath ) => {
  * @return {string}             Build path
  */
 function getBuildPath( file, buildFolder ) {
-	const pkgName = getPackageName( file );
+	// if the file has extension of ts, replace with js
+	const fileName = file.replace( '.ts', '.js' );
+	const pkgName = getPackageName( fileName );
 	const pkgSrcPath = path.resolve( PACKAGES_DIR, pkgName, SRC_DIR );
 	const pkgBuildPath = path.resolve( PACKAGES_DIR, pkgName, buildFolder );
-	const relativeToSrcPath = path.relative( pkgSrcPath, file );
+	const relativeToSrcPath = path.relative( pkgSrcPath, fileName );
 	return path.resolve( pkgBuildPath, relativeToSrcPath );
 }
 
@@ -198,7 +200,7 @@ function buildJsFileFor( file, silent, environment ) {
  */
 async function buildPackage( packagePath ) {
 	const srcDir = path.resolve( packagePath, SRC_DIR );
-	const jsFiles = glob.sync( `${ srcDir }/**/*.js`, {
+	const jsFiles = glob.sync( `${ srcDir }/**/*.{ts,tsx,js}`, {
 		ignore: [
 			`${ srcDir }/**/test/**/*.js`,
 			`${ srcDir }/**/__mocks__/**/*.js`,
@@ -212,7 +214,9 @@ async function buildPackage( packagePath ) {
 	process.stdout.write( `${ path.basename( packagePath ) }\n` );
 
 	// Build js files individually.
-	jsFiles.forEach( ( file ) => buildJsFile( file, true ) );
+	jsFiles.forEach( ( file ) => {
+		buildJsFile( file, true );
+	} );
 
 	process.stdout.write( `${ DONE }\n` );
 }
diff --git a/plugins/woocommerce-admin/bin/packages/get-babel-config.js b/plugins/woocommerce-admin/bin/packages/get-babel-config.js
index 37b2b8b2446..49e4b8a7b28 100644
--- a/plugins/woocommerce-admin/bin/packages/get-babel-config.js
+++ b/plugins/woocommerce-admin/bin/packages/get-babel-config.js
@@ -22,13 +22,16 @@ const overrideOptions = ( target, targetName, options ) => {
 const babelConfigs = {
 	main: Object.assign( {}, babelDefaultConfig, {
 		plugins,
-		presets: map( babelDefaultConfig.presets, ( preset ) =>
-			overrideOptions( preset, '@babel/preset-env', {
-				modules: 'commonjs',
-				corejs: '3',
-				useBuiltIns: 'usage',
-			} )
-		),
+		presets: [
+			[ '@babel/preset-typescript' ],
+			...map( babelDefaultConfig.presets, ( preset ) =>
+				overrideOptions( preset, '@babel/preset-env', {
+					modules: 'commonjs',
+					corejs: '3',
+					useBuiltIns: 'usage',
+				} )
+			),
+		],
 	} ),
 	module: Object.assign( {}, babelDefaultConfig, {
 		plugins: map( plugins, ( plugin ) =>
@@ -36,13 +39,16 @@ const babelConfigs = {
 				useESModules: true,
 			} )
 		),
-		presets: map( babelDefaultConfig.presets, ( preset ) =>
-			overrideOptions( preset, '@babel/preset-env', {
-				modules: false,
-				corejs: '3',
-				useBuiltIns: 'usage',
-			} )
-		),
+		presets: [
+			[ '@babel/preset-typescript' ],
+			...map( babelDefaultConfig.presets, ( preset ) =>
+				overrideOptions( preset, '@babel/preset-env', {
+					modules: false,
+					corejs: '3',
+					useBuiltIns: 'usage',
+				} )
+			),
+		],
 	} ),
 };
 
diff --git a/plugins/woocommerce-admin/client/dashboard/index.js b/plugins/woocommerce-admin/client/dashboard/index.js
index d7e257af068..2bbebab8061 100644
--- a/plugins/woocommerce-admin/client/dashboard/index.js
+++ b/plugins/woocommerce-admin/client/dashboard/index.js
@@ -2,14 +2,6 @@
  * External dependencies
  */
 import { Component, Suspense, lazy } from '@wordpress/element';
-import { compose } from '@wordpress/compose';
-import { withSelect } from '@wordpress/data';
-import { identity } from 'lodash';
-import { getSetting } from '@woocommerce/wc-admin-settings';
-import {
-	ONBOARDING_STORE_NAME,
-	withOnboardingHydration,
-} from '@woocommerce/data';
 import { Spinner } from '@woocommerce/components';
 
 /**
@@ -37,16 +29,4 @@ class Dashboard extends Component {
 	}
 }
 
-const onboardingData = getSetting( 'onboarding', {} );
-
-export default compose(
-	!! onboardingData.tasksStatus
-		? withOnboardingHydration( { tasksStatus: onboardingData.tasksStatus } )
-		: identity,
-	withSelect( ( select ) => {
-		const { getProfileItems } = select( ONBOARDING_STORE_NAME );
-		const profileItems = getProfileItems();
-
-		return { profileItems };
-	} )
-)( Dashboard );
+export default Dashboard;
diff --git a/plugins/woocommerce-admin/client/homescreen/index.js b/plugins/woocommerce-admin/client/homescreen/index.tsx
similarity index 63%
rename from plugins/woocommerce-admin/client/homescreen/index.js
rename to plugins/woocommerce-admin/client/homescreen/index.tsx
index b2787e01df3..1305a4fa72b 100644
--- a/plugins/woocommerce-admin/client/homescreen/index.js
+++ b/plugins/woocommerce-admin/client/homescreen/index.tsx
@@ -8,19 +8,26 @@ import { getSetting } from '@woocommerce/wc-admin-settings';
 import {
 	ONBOARDING_STORE_NAME,
 	withOnboardingHydration,
+	WCDataSelector,
 } from '@woocommerce/data';
 import { getHistory, getNewPath } from '@woocommerce/navigation';
-
+import type { History } from 'history';
 /**
  * Internal dependencies
  */
 import Layout from './layout';
 
-const Homescreen = ( { profileItems, query } ) => {
+type HomescreenProps = ReturnType< typeof withSelectHandler > & {
+	query: Record< string, string >;
+};
+
+const Homescreen = ( { profileItems, query }: HomescreenProps ) => {
 	const { completed: profilerCompleted, skipped: profilerSkipped } =
 		profileItems || {};
 	if ( ! profilerCompleted && ! profilerSkipped ) {
-		getHistory().push( getNewPath( {}, '/setup-wizard', {} ) );
+		( getHistory() as History ).push(
+			getNewPath( {}, '/setup-wizard', {} )
+		);
 	}
 
 	return <Layout query={ query } />;
@@ -28,6 +35,13 @@ const Homescreen = ( { profileItems, query } ) => {
 
 const onboardingData = getSetting( 'onboarding', {} );
 
+const withSelectHandler = ( select: WCDataSelector ) => {
+	const { getProfileItems } = select( ONBOARDING_STORE_NAME );
+	const profileItems = getProfileItems();
+
+	return { profileItems };
+};
+
 export default compose(
 	onboardingData.profile || onboardingData.tasksStatus
 		? withOnboardingHydration( {
@@ -35,10 +49,5 @@ export default compose(
 				tasksStatus: onboardingData.tasksStatus,
 		  } )
 		: identity,
-	withSelect( ( select ) => {
-		const { getProfileItems } = select( ONBOARDING_STORE_NAME );
-		const profileItems = getProfileItems();
-
-		return { profileItems };
-	} )
+	withSelect( withSelectHandler )
 )( Homescreen );
diff --git a/plugins/woocommerce-admin/package-lock.json b/plugins/woocommerce-admin/package-lock.json
index f5aa8f9919b..e86e2cb9361 100644
--- a/plugins/woocommerce-admin/package-lock.json
+++ b/plugins/woocommerce-admin/package-lock.json
@@ -9139,6 +9139,12 @@
 				"@types/unist": "*"
 			}
 		},
+		"@types/history": {
+			"version": "4.7.8",
+			"resolved": "https://registry.npmjs.org/@types/history/-/history-4.7.8.tgz",
+			"integrity": "sha512-S78QIYirQcUoo6UJZx9CSP0O2ix9IaeAXwQi26Rhr/+mg7qqPy8TzaxHSUut7eGjL8WmLccT7/MXf304WjqHcA==",
+			"dev": true
+		},
 		"@types/html-minifier-terser": {
 			"version": "5.1.1",
 			"resolved": "https://registry.npmjs.org/@types/html-minifier-terser/-/html-minifier-terser-5.1.1.tgz",
@@ -9315,6 +9321,12 @@
 				"@types/node": "*"
 			}
 		},
+		"@types/lodash": {
+			"version": "4.14.168",
+			"resolved": "https://registry.npmjs.org/@types/lodash/-/lodash-4.14.168.tgz",
+			"integrity": "sha512-oVfRvqHV/V6D1yifJbVRU3TMp8OT6o6BG+U9MkwuJ3U8/CsDHvalRpsxBqivn71ztOFZBTfJMvETbqHiaNSj7Q==",
+			"dev": true
+		},
 		"@types/markdown-to-jsx": {
 			"version": "6.11.3",
 			"resolved": "https://registry.npmjs.org/@types/markdown-to-jsx/-/markdown-to-jsx-6.11.3.tgz",
diff --git a/plugins/woocommerce-admin/package.json b/plugins/woocommerce-admin/package.json
index e08308f1676..6e0ff6965d3 100644
--- a/plugins/woocommerce-admin/package.json
+++ b/plugins/woocommerce-admin/package.json
@@ -156,7 +156,9 @@
 		"@testing-library/react-hooks": "3.7.0",
 		"@testing-library/user-event": "12.8.3",
 		"@types/expect-puppeteer": "^4.4.5",
+		"@types/history": "^4.7.8",
 		"@types/jest": "^26.0.20",
+		"@types/lodash": "^4.14.168",
 		"@types/puppeteer": "^5.4.3",
 		"@typescript-eslint/eslint-plugin": "4.19.0",
 		"@woocommerce/api": "^0.1.1",
diff --git a/plugins/woocommerce-admin/packages/data/package.json b/plugins/woocommerce-admin/packages/data/package.json
index fe8d33c5e0c..f9e893f056c 100644
--- a/plugins/woocommerce-admin/packages/data/package.json
+++ b/plugins/woocommerce-admin/packages/data/package.json
@@ -27,5 +27,8 @@
 	},
 	"publishConfig": {
 		"access": "public"
+	},
+	"peerDependencies": {
+		"@wordpress/core-data": "^2.24.2"
 	}
 }
diff --git a/plugins/woocommerce-admin/packages/data/src/export/constants.js b/plugins/woocommerce-admin/packages/data/src/export/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/export/constants.js
rename to plugins/woocommerce-admin/packages/data/src/export/constants.ts
diff --git a/plugins/woocommerce-admin/packages/data/src/import/constants.js b/plugins/woocommerce-admin/packages/data/src/import/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/import/constants.js
rename to plugins/woocommerce-admin/packages/data/src/import/constants.ts
diff --git a/plugins/woocommerce-admin/packages/data/src/index.js b/plugins/woocommerce-admin/packages/data/src/index.js
deleted file mode 100644
index d602eb205c7..00000000000
--- a/plugins/woocommerce-admin/packages/data/src/index.js
+++ /dev/null
@@ -1,62 +0,0 @@
-/**
- * External dependencies
- */
-import '@wordpress/core-data';
-
-export { SETTINGS_STORE_NAME } from './settings';
-export { withSettingsHydration } from './settings/with-settings-hydration';
-export { useSettings } from './settings/use-settings';
-
-export { PLUGINS_STORE_NAME } from './plugins';
-export { pluginNames } from './plugins/constants';
-export { withPluginsHydration } from './plugins/with-plugins-hydration';
-
-export { ONBOARDING_STORE_NAME } from './onboarding';
-export { withOnboardingHydration } from './onboarding/with-onboarding-hydration';
-
-export { USER_STORE_NAME } from './user';
-export { withCurrentUserHydration } from './user/with-current-user-hydration';
-export { useUser } from './user/use-user';
-export { useUserPreferences } from './user/use-user-preferences';
-
-export { OPTIONS_STORE_NAME } from './options';
-export { withOptionsHydration } from './options/with-options-hydration';
-
-export { REVIEWS_STORE_NAME } from './reviews';
-
-export { NOTES_STORE_NAME } from './notes';
-
-export { REPORTS_STORE_NAME } from './reports';
-
-export { ITEMS_STORE_NAME } from './items';
-export { getLeaderboard, searchItemsByString } from './items/utils';
-
-export { NAVIGATION_STORE_NAME } from './navigation';
-export { withNavigationHydration } from './navigation/with-navigation-hydration';
-
-export {
-	getFilterQuery,
-	getSummaryNumbers,
-	getReportTableData,
-	getReportTableQuery,
-	getReportChartData,
-	getTooltipValueFormat,
-} from './reports/utils';
-
-export {
-	MAX_PER_PAGE,
-	QUERY_DEFAULTS,
-	NAMESPACE,
-	WC_ADMIN_NAMESPACE,
-	WCS_NAMESPACE,
-	SECOND,
-	MINUTE,
-	HOUR,
-	DAY,
-	WEEK,
-	MONTH,
-} from './constants';
-
-export { EXPORT_STORE_NAME } from './export';
-
-export { IMPORT_STORE_NAME } from './import';
diff --git a/plugins/woocommerce-admin/packages/data/src/index.ts b/plugins/woocommerce-admin/packages/data/src/index.ts
new file mode 100644
index 00000000000..0a43a6defc9
--- /dev/null
+++ b/plugins/woocommerce-admin/packages/data/src/index.ts
@@ -0,0 +1,119 @@
+/**
+ * External dependencies
+ */
+import '@wordpress/core-data';
+
+/**
+ * Internal dependencies
+ */
+import type { REVIEWS_STORE_NAME } from './reviews';
+import type { SETTINGS_STORE_NAME } from './settings';
+import type { PLUGINS_STORE_NAME } from './plugins';
+import type { ONBOARDING_STORE_NAME } from './onboarding';
+import type { USER_STORE_NAME } from './user';
+import type { OPTIONS_STORE_NAME } from './options';
+import type { NAVIGATION_STORE_NAME } from './navigation';
+import type { NOTES_STORE_NAME } from './notes';
+import type { REPORTS_STORE_NAME } from './reports';
+import type { ITEMS_STORE_NAME } from './items';
+import { OnboardingSelectors } from './onboarding/selectors';
+import { WPDataSelectors } from './types';
+
+export { SETTINGS_STORE_NAME } from './settings';
+export { withSettingsHydration } from './settings/with-settings-hydration';
+export { useSettings } from './settings/use-settings';
+
+export { PLUGINS_STORE_NAME } from './plugins';
+export { pluginNames } from './plugins/constants';
+export { withPluginsHydration } from './plugins/with-plugins-hydration';
+
+export { ONBOARDING_STORE_NAME } from './onboarding';
+export { withOnboardingHydration } from './onboarding/with-onboarding-hydration';
+
+export { USER_STORE_NAME } from './user';
+export { withCurrentUserHydration } from './user/with-current-user-hydration';
+export { useUser } from './user/use-user';
+export { useUserPreferences } from './user/use-user-preferences';
+
+export { OPTIONS_STORE_NAME } from './options';
+export { withOptionsHydration } from './options/with-options-hydration';
+
+export { REVIEWS_STORE_NAME } from './reviews';
+
+export { NOTES_STORE_NAME } from './notes';
+
+export { REPORTS_STORE_NAME } from './reports';
+
+export { ITEMS_STORE_NAME } from './items';
+export { getLeaderboard, searchItemsByString } from './items/utils';
+
+export { NAVIGATION_STORE_NAME } from './navigation';
+export { withNavigationHydration } from './navigation/with-navigation-hydration';
+
+export {
+	getFilterQuery,
+	getSummaryNumbers,
+	getReportTableData,
+	getReportTableQuery,
+	getReportChartData,
+	getTooltipValueFormat,
+} from './reports/utils';
+
+export {
+	MAX_PER_PAGE,
+	QUERY_DEFAULTS,
+	NAMESPACE,
+	WC_ADMIN_NAMESPACE,
+	WCS_NAMESPACE,
+	SECOND,
+	MINUTE,
+	HOUR,
+	DAY,
+	WEEK,
+	MONTH,
+} from './constants';
+
+export { EXPORT_STORE_NAME } from './export';
+
+export { IMPORT_STORE_NAME } from './import';
+
+type WCDataStoreName =
+	| typeof REVIEWS_STORE_NAME
+	| typeof SETTINGS_STORE_NAME
+	| typeof PLUGINS_STORE_NAME
+	| typeof ONBOARDING_STORE_NAME
+	| typeof USER_STORE_NAME
+	| typeof OPTIONS_STORE_NAME
+	| typeof NAVIGATION_STORE_NAME
+	| typeof NOTES_STORE_NAME
+	| typeof REPORTS_STORE_NAME
+	| typeof ITEMS_STORE_NAME;
+
+// As we add types to all the package selectors we can fill out these unknown types with real ones. See one
+// of the already typed selectors for an example of how you can do this.
+type WCSelectorType< T > = T extends typeof REVIEWS_STORE_NAME
+	? WPDataSelectors
+	: T extends typeof SETTINGS_STORE_NAME
+	? WPDataSelectors
+	: T extends typeof PLUGINS_STORE_NAME
+	? WPDataSelectors
+	: T extends typeof ONBOARDING_STORE_NAME
+	? OnboardingSelectors
+	: T extends typeof USER_STORE_NAME
+	? WPDataSelectors
+	: T extends typeof OPTIONS_STORE_NAME
+	? WPDataSelectors
+	: T extends typeof NAVIGATION_STORE_NAME
+	? WPDataSelectors
+	: T extends typeof NOTES_STORE_NAME
+	? WPDataSelectors
+	: T extends typeof REPORTS_STORE_NAME
+	? WPDataSelectors
+	: T extends typeof ITEMS_STORE_NAME
+	? WPDataSelectors
+	: never;
+
+export interface WCDataSelector {
+	< T extends WCDataStoreName >( storeName: T ): WCSelectorType< T >;
+}
+export * from './onboarding/selectors';
diff --git a/plugins/woocommerce-admin/packages/data/src/items/constants.js b/plugins/woocommerce-admin/packages/data/src/items/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/items/constants.js
rename to plugins/woocommerce-admin/packages/data/src/items/constants.ts
diff --git a/plugins/woocommerce-admin/packages/data/src/navigation/constants.js b/plugins/woocommerce-admin/packages/data/src/navigation/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/navigation/constants.js
rename to plugins/woocommerce-admin/packages/data/src/navigation/constants.ts
diff --git a/plugins/woocommerce-admin/packages/data/src/notes/constants.js b/plugins/woocommerce-admin/packages/data/src/notes/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/notes/constants.js
rename to plugins/woocommerce-admin/packages/data/src/notes/constants.ts
diff --git a/plugins/woocommerce-admin/packages/data/src/onboarding/constants.js b/plugins/woocommerce-admin/packages/data/src/onboarding/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/onboarding/constants.js
rename to plugins/woocommerce-admin/packages/data/src/onboarding/constants.ts
diff --git a/plugins/woocommerce-admin/packages/data/src/onboarding/reducer.js b/plugins/woocommerce-admin/packages/data/src/onboarding/reducer.js
index e9af5ca184c..69810822bbd 100644
--- a/plugins/woocommerce-admin/packages/data/src/onboarding/reducer.js
+++ b/plugins/woocommerce-admin/packages/data/src/onboarding/reducer.js
@@ -3,13 +3,29 @@
  */
 import TYPES from './action-types';
 
-const onboarding = (
-	state = {
-		errors: {},
-		profileItems: {},
-		requesting: {},
-		tasksStatus: {},
+export const defaultState = {
+	errors: {},
+	profileItems: {
+		business_extensions: null,
+		completed: null,
+		industry: null,
+		other_platform: null,
+		other_platform_name: null,
+		product_count: null,
+		product_types: null,
+		revenue: null,
+		selling_venues: null,
+		setup_client: null,
+		skipped: null,
+		theme: null,
+		wccom_connected: null,
 	},
+	requesting: {},
+	tasksStatus: {},
+};
+
+const onboarding = (
+	state = defaultState,
 	{ type, profileItems, replace, error, isRequesting, selector, tasksStatus }
 ) => {
 	switch ( type ) {
diff --git a/plugins/woocommerce-admin/packages/data/src/onboarding/selectors.js b/plugins/woocommerce-admin/packages/data/src/onboarding/selectors.js
deleted file mode 100644
index 3fcd6738acb..00000000000
--- a/plugins/woocommerce-admin/packages/data/src/onboarding/selectors.js
+++ /dev/null
@@ -1,15 +0,0 @@
-export const getProfileItems = ( state ) => {
-	return state.profileItems || {};
-};
-
-export const getTasksStatus = ( state ) => {
-	return state.tasksStatus || {};
-};
-
-export const getOnboardingError = ( state, selector ) => {
-	return state.errors[ selector ] || false;
-};
-
-export const isOnboardingRequesting = ( state, selector ) => {
-	return state.requesting[ selector ] || false;
-};
diff --git a/plugins/woocommerce-admin/packages/data/src/onboarding/selectors.ts b/plugins/woocommerce-admin/packages/data/src/onboarding/selectors.ts
new file mode 100644
index 00000000000..1a80a2033d0
--- /dev/null
+++ b/plugins/woocommerce-admin/packages/data/src/onboarding/selectors.ts
@@ -0,0 +1,114 @@
+/**
+ * Internal dependencies
+ */
+import { WPDataSelectors } from '../types';
+
+export const getProfileItems = (
+	state: OnboardingState
+): ProfileItemsState | Record< string, never > => {
+	return state.profileItems || {};
+};
+
+export const getTasksStatus = (
+	state: OnboardingState
+): TasksStatusState | Record< string, never > => {
+	return state.tasksStatus || {};
+};
+
+export const getOnboardingError = (
+	state: OnboardingState,
+	selector: string
+): unknown | false => {
+	return state.errors[ selector ] || false;
+};
+
+export const isOnboardingRequesting = (
+	state: OnboardingState,
+	selector: string
+): boolean => {
+	return state.requesting[ selector ] || false;
+};
+
+// Types
+export type OnboardingSelectors = {
+	getProfileItems: () => ReturnType< typeof getProfileItems >;
+	getTasksStatus: () => ReturnType< typeof getTasksStatus >;
+	getOnboardingError: () => ReturnType< typeof getOnboardingError >;
+	isOnboardingRequesting: () => ReturnType< typeof isOnboardingRequesting >;
+} & WPDataSelectors;
+
+export type OnboardingState = {
+	profileItems: ProfileItemsState;
+	tasksStatus: TasksStatusState;
+	// TODO clarify what the error record's type is
+	errors: Record< string, unknown >;
+	requesting: Record< string, boolean >;
+};
+
+export type TasksStatusState = {
+	automatedTaxSupportedCountries: string[];
+	enabledPaymentGateways: string[];
+	hasHomepage: boolean;
+	hasPaymentGateway: boolean;
+	hasPhysicalProducts: boolean;
+	hasProducts: boolean;
+	isAppearanceComplete: boolean;
+	isTaxComplete: boolean;
+	shippingZonesCount: number;
+	stripeSupportedCountries: string[];
+	stylesheet: string;
+	taxJarActivated: boolean;
+	// TODO - fill out this type
+	themeMods: unknown;
+	wcPayIsConnected: false;
+};
+
+export type Industry = {
+	slug: string;
+};
+
+export type ProductCount = '0' | '1-10' | '11-100' | '101 - 1000' | '1000+';
+
+export type ProductTypeSlug =
+	| 'physical'
+	| 'bookings'
+	| 'download'
+	| 'memberships'
+	| 'product-add-ons'
+	| 'product-bundles'
+	| 'subscriptions';
+
+export type OtherPlatformSlug =
+	| 'shopify'
+	| 'bigcommerce'
+	| 'wix'
+	| 'amazon'
+	| 'ebay'
+	| 'etsy'
+	| 'squarespace'
+	| 'other';
+
+export type RevenueTypeSlug =
+	| 'none'
+	| 'rather-not-say'
+	| 'up-to-2500'
+	| '2500-10000'
+	| '10000-50000'
+	| '50000-250000'
+	| 'more-than-250000';
+
+export type ProfileItemsState = {
+	business_extensions: [  ] | null;
+	completed: boolean | null;
+	industry: Industry[] | null;
+	other_platform: OtherPlatformSlug | null;
+	other_platform_name: string | null;
+	product_count: ProductCount | null;
+	product_types: ProductTypeSlug[] | null;
+	revenue: RevenueTypeSlug | null;
+	selling_venues: string | null;
+	setup_client: boolean | null;
+	skipped: boolean | null;
+	theme: string | null;
+	wccom_connected: boolean | null;
+};
diff --git a/plugins/woocommerce-admin/packages/data/src/onboarding/test/reducer.js b/plugins/woocommerce-admin/packages/data/src/onboarding/test/reducer.js
index ed7c314d625..792932f03a8 100644
--- a/plugins/woocommerce-admin/packages/data/src/onboarding/test/reducer.js
+++ b/plugins/woocommerce-admin/packages/data/src/onboarding/test/reducer.js
@@ -5,21 +5,13 @@
 /**
  * Internal dependencies
  */
-import reducer from '../reducer';
+import reducer, { defaultState } from '../reducer';
 import TYPES from '../action-types';
 
-const defaultState = {
-	errors: {},
-	profileItems: {},
-	requesting: {},
-	tasksStatus: {},
-};
-
 describe( 'plugins reducer', () => {
 	it( 'should return a default state', () => {
 		const state = reducer( undefined, {} );
 		expect( state ).toEqual( defaultState );
-		expect( state ).not.toBe( defaultState );
 	} );
 
 	it( 'should handle SET_PROFILE_ITEMS', () => {
diff --git a/plugins/woocommerce-admin/packages/data/src/options/constants.js b/plugins/woocommerce-admin/packages/data/src/options/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/options/constants.js
rename to plugins/woocommerce-admin/packages/data/src/options/constants.ts
diff --git a/plugins/woocommerce-admin/packages/data/src/plugins/constants.js b/plugins/woocommerce-admin/packages/data/src/plugins/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/plugins/constants.js
rename to plugins/woocommerce-admin/packages/data/src/plugins/constants.ts
diff --git a/plugins/woocommerce-admin/packages/data/src/reports/constants.js b/plugins/woocommerce-admin/packages/data/src/reports/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/reports/constants.js
rename to plugins/woocommerce-admin/packages/data/src/reports/constants.ts
diff --git a/plugins/woocommerce-admin/packages/data/src/reviews/constants.js b/plugins/woocommerce-admin/packages/data/src/reviews/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/reviews/constants.js
rename to plugins/woocommerce-admin/packages/data/src/reviews/constants.ts
diff --git a/plugins/woocommerce-admin/packages/data/src/settings/constants.js b/plugins/woocommerce-admin/packages/data/src/settings/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/settings/constants.js
rename to plugins/woocommerce-admin/packages/data/src/settings/constants.ts
diff --git a/plugins/woocommerce-admin/packages/data/src/types.ts b/plugins/woocommerce-admin/packages/data/src/types.ts
new file mode 100644
index 00000000000..e16213a7904
--- /dev/null
+++ b/plugins/woocommerce-admin/packages/data/src/types.ts
@@ -0,0 +1,8 @@
+// Type for the basic selectors built into @wordpress/data, note these
+// types define the interface for the public selectors, so state is not an
+// argument.
+export type WPDataSelectors = {
+	hasStartedResolution: ( selector: string, args?: string[] ) => boolean;
+	hasFinishedResolution: ( selector: string, args?: string[] ) => boolean;
+	isResolving: ( selector: string, args: [  ] ) => boolean;
+};
diff --git a/plugins/woocommerce-admin/packages/data/src/user/constants.js b/plugins/woocommerce-admin/packages/data/src/user/constants.ts
similarity index 100%
rename from plugins/woocommerce-admin/packages/data/src/user/constants.js
rename to plugins/woocommerce-admin/packages/data/src/user/constants.ts
diff --git a/plugins/woocommerce-admin/tests/js/jest.config.json b/plugins/woocommerce-admin/tests/js/jest.config.json
index 3898074d061..59bb94397bc 100644
--- a/plugins/woocommerce-admin/tests/js/jest.config.json
+++ b/plugins/woocommerce-admin/tests/js/jest.config.json
@@ -27,7 +27,7 @@
 		"**/?(*.)test.[jt]s"
 	],
 	"transform": {
-		"^.+\\.[t|j]s?$": "babel-jest"
+		"^.+\\.[jt]sx?$": "babel-jest"
 	},
 	"testPathIgnorePatterns": [
 		"/node_modules/",
diff --git a/plugins/woocommerce-admin/typings/index.d.ts b/plugins/woocommerce-admin/typings/index.d.ts
index 99c6b9ae608..700e32cd5e0 100644
--- a/plugins/woocommerce-admin/typings/index.d.ts
+++ b/plugins/woocommerce-admin/typings/index.d.ts
@@ -1 +1,3 @@
 declare module '@woocommerce/e2e-utils';
+declare module '@wordpress/data';
+declare module '@wordpress/compose';
diff --git a/plugins/woocommerce-admin/webpack.config.js b/plugins/woocommerce-admin/webpack.config.js
index 6e632f44e77..c6f195cf0b8 100644
--- a/plugins/woocommerce-admin/webpack.config.js
+++ b/plugins/woocommerce-admin/webpack.config.js
@@ -88,7 +88,11 @@ const webpackConfig = {
 			},
 			{
 				test: /\.(t|j)sx?$/,
-				exclude: /node_modules(\/|\\)(?!(debug))/,
+				exclude: [
+					/node_modules(\/|\\)(?!(debug))/,
+					/build/,
+					/build-module/,
+				],
 				use: {
 					loader: 'babel-loader',
 					options: {