diff --git a/src/core/server/rendering/bootstrap/bootstrap_renderer.test.mocks.ts b/src/core/server/rendering/bootstrap/bootstrap_renderer.test.mocks.ts
new file mode 100644
index 0000000000000..2b3a6788a465d
--- /dev/null
+++ b/src/core/server/rendering/bootstrap/bootstrap_renderer.test.mocks.ts
@@ -0,0 +1,27 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+export const renderTemplateMock = jest.fn();
+jest.doMock('./render_template', () => ({
+  renderTemplate: renderTemplateMock,
+}));
+
+export const getThemeTagMock = jest.fn();
+jest.doMock('./get_theme_tag', () => ({
+  getThemeTag: getThemeTagMock,
+}));
+
+export const getPluginsBundlePathsMock = jest.fn();
+jest.doMock('./get_plugin_bundle_paths', () => ({
+  getPluginsBundlePaths: getPluginsBundlePathsMock,
+}));
+
+export const getJsDependencyPathsMock = jest.fn();
+jest.doMock('./get_js_dependency_paths', () => ({
+  getJsDependencyPaths: getJsDependencyPathsMock,
+}));
diff --git a/src/core/server/rendering/bootstrap/bootstrap_renderer.test.ts b/src/core/server/rendering/bootstrap/bootstrap_renderer.test.ts
new file mode 100644
index 0000000000000..3803d38a968c1
--- /dev/null
+++ b/src/core/server/rendering/bootstrap/bootstrap_renderer.test.ts
@@ -0,0 +1,241 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import {
+  renderTemplateMock,
+  getPluginsBundlePathsMock,
+  getThemeTagMock,
+  getJsDependencyPathsMock,
+} from './bootstrap_renderer.test.mocks';
+
+import { PackageInfo } from '@kbn/config';
+import { UiPlugins } from '../../plugins';
+import { httpServiceMock } from '../../http/http_service.mock';
+import { httpServerMock } from '../../http/http_server.mocks';
+import { AuthStatus } from '../../http';
+import { uiSettingsServiceMock } from '../../ui_settings/ui_settings_service.mock';
+import { bootstrapRendererFactory, BootstrapRenderer } from './bootstrap_renderer';
+
+const createPackageInfo = (parts: Partial<PackageInfo> = {}): PackageInfo => ({
+  branch: 'master',
+  buildNum: 42,
+  buildSha: 'buildSha',
+  dist: false,
+  version: '8.0.0',
+  ...parts,
+});
+
+const createUiPlugins = (): UiPlugins => ({
+  public: new Map(),
+  internal: new Map(),
+  browserConfigs: new Map(),
+});
+
+describe('bootstrapRenderer', () => {
+  let auth: ReturnType<typeof httpServiceMock.createAuth>;
+  let uiSettingsClient: ReturnType<typeof uiSettingsServiceMock.createClient>;
+  let renderer: BootstrapRenderer;
+  let uiPlugins: UiPlugins;
+  let packageInfo: PackageInfo;
+
+  beforeEach(() => {
+    auth = httpServiceMock.createAuth();
+    uiSettingsClient = uiSettingsServiceMock.createClient();
+    uiPlugins = createUiPlugins();
+    packageInfo = createPackageInfo();
+
+    getThemeTagMock.mockReturnValue('v8light');
+    getPluginsBundlePathsMock.mockReturnValue(new Map());
+    renderTemplateMock.mockReturnValue('__rendered__');
+    getJsDependencyPathsMock.mockReturnValue([]);
+
+    renderer = bootstrapRendererFactory({
+      auth,
+      packageInfo,
+      uiPlugins,
+      serverBasePath: '/base-path',
+    });
+  });
+
+  afterEach(() => {
+    getThemeTagMock.mockReset();
+    getPluginsBundlePathsMock.mockReset();
+    renderTemplateMock.mockReset();
+    getJsDependencyPathsMock.mockReset();
+  });
+
+  describe('when the auth status is `authenticated`', () => {
+    beforeEach(() => {
+      auth.get.mockReturnValue({
+        status: 'authenticated' as AuthStatus,
+        state: {},
+      });
+    });
+
+    it('calls uiSettingsClient.get with the correct parameters', async () => {
+      const request = httpServerMock.createKibanaRequest();
+
+      await renderer({
+        request,
+        uiSettingsClient,
+      });
+
+      expect(uiSettingsClient.get).toHaveBeenCalledTimes(2);
+      expect(uiSettingsClient.get).toHaveBeenCalledWith('theme:darkMode');
+      expect(uiSettingsClient.get).toHaveBeenCalledWith('theme:version');
+    });
+
+    it('calls getThemeTag with the correct parameters', async () => {
+      uiSettingsClient.get.mockImplementation((settingName) => {
+        return Promise.resolve(settingName === 'theme:darkMode' ? true : 'v8');
+      });
+
+      const request = httpServerMock.createKibanaRequest();
+
+      await renderer({
+        request,
+        uiSettingsClient,
+      });
+
+      expect(getThemeTagMock).toHaveBeenCalledTimes(1);
+      expect(getThemeTagMock).toHaveBeenCalledWith({
+        themeVersion: 'v8',
+        darkMode: true,
+      });
+    });
+  });
+
+  describe('when the auth status is `unknown`', () => {
+    beforeEach(() => {
+      auth.get.mockReturnValue({
+        status: 'unknown' as AuthStatus,
+        state: {},
+      });
+    });
+
+    it('calls uiSettingsClient.get with the correct parameters', async () => {
+      const request = httpServerMock.createKibanaRequest();
+
+      await renderer({
+        request,
+        uiSettingsClient,
+      });
+
+      expect(uiSettingsClient.get).toHaveBeenCalledTimes(2);
+      expect(uiSettingsClient.get).toHaveBeenCalledWith('theme:darkMode');
+      expect(uiSettingsClient.get).toHaveBeenCalledWith('theme:version');
+    });
+
+    it('calls getThemeTag with the correct parameters', async () => {
+      uiSettingsClient.get.mockImplementation((settingName) => {
+        return Promise.resolve(settingName === 'theme:darkMode' ? true : 'v8');
+      });
+
+      const request = httpServerMock.createKibanaRequest();
+
+      await renderer({
+        request,
+        uiSettingsClient,
+      });
+
+      expect(getThemeTagMock).toHaveBeenCalledTimes(1);
+      expect(getThemeTagMock).toHaveBeenCalledWith({
+        themeVersion: 'v8',
+        darkMode: true,
+      });
+    });
+  });
+
+  describe('when the auth status is `unauthenticated`', () => {
+    beforeEach(() => {
+      auth.get.mockReturnValue({
+        status: 'unauthenticated' as AuthStatus,
+        state: {},
+      });
+    });
+
+    it('does not call uiSettingsClient.get', async () => {
+      const request = httpServerMock.createKibanaRequest();
+
+      await renderer({
+        request,
+        uiSettingsClient,
+      });
+
+      expect(uiSettingsClient.get).not.toHaveBeenCalled();
+    });
+
+    it('calls getThemeTag with the default parameters', async () => {
+      const request = httpServerMock.createKibanaRequest();
+
+      await renderer({
+        request,
+        uiSettingsClient,
+      });
+
+      expect(getThemeTagMock).toHaveBeenCalledTimes(1);
+      expect(getThemeTagMock).toHaveBeenCalledWith({
+        themeVersion: 'v7',
+        darkMode: false,
+      });
+    });
+  });
+
+  it('calls getPluginsBundlePaths with the correct parameters', async () => {
+    const request = httpServerMock.createKibanaRequest();
+
+    await renderer({
+      request,
+      uiSettingsClient,
+    });
+
+    expect(getPluginsBundlePathsMock).toHaveBeenCalledTimes(1);
+    expect(getPluginsBundlePathsMock).toHaveBeenCalledWith({
+      uiPlugins,
+      regularBundlePath: '/base-path/42/bundles',
+    });
+  });
+
+  // here
+  it('calls getJsDependencyPaths with the correct parameters', async () => {
+    const pluginsBundlePaths = new Map<string, unknown>();
+
+    getPluginsBundlePathsMock.mockReturnValue(pluginsBundlePaths);
+    const request = httpServerMock.createKibanaRequest();
+
+    await renderer({
+      request,
+      uiSettingsClient,
+    });
+
+    expect(getJsDependencyPathsMock).toHaveBeenCalledTimes(1);
+    expect(getJsDependencyPathsMock).toHaveBeenCalledWith(
+      '/base-path/42/bundles',
+      pluginsBundlePaths
+    );
+  });
+
+  it('calls renderTemplate with the correct parameters', async () => {
+    getThemeTagMock.mockReturnValue('customThemeTag');
+    getJsDependencyPathsMock.mockReturnValue(['path-1', 'path-2']);
+
+    const request = httpServerMock.createKibanaRequest();
+
+    await renderer({
+      request,
+      uiSettingsClient,
+    });
+
+    expect(renderTemplateMock).toHaveBeenCalledTimes(1);
+    expect(renderTemplateMock).toHaveBeenCalledWith({
+      themeTag: 'customThemeTag',
+      jsDependencyPaths: ['path-1', 'path-2'],
+      publicPathMap: expect.any(String),
+    });
+  });
+});
diff --git a/src/core/server/rendering/bootstrap/bootstrap_renderer.ts b/src/core/server/rendering/bootstrap/bootstrap_renderer.ts
index adb510c6f0512..cff593e5c5aa9 100644
--- a/src/core/server/rendering/bootstrap/bootstrap_renderer.ts
+++ b/src/core/server/rendering/bootstrap/bootstrap_renderer.ts
@@ -7,12 +7,12 @@
  */
 
 import { createHash } from 'crypto';
-import * as UiSharedDeps from '@kbn/ui-shared-deps';
 import { PackageInfo } from '@kbn/config';
 import { UiPlugins } from '../../plugins';
 import { IUiSettingsClient } from '../../ui_settings';
 import { HttpAuth, KibanaRequest } from '../../http';
 import { getPluginsBundlePaths } from './get_plugin_bundle_paths';
+import { getJsDependencyPaths } from './get_js_dependency_paths';
 import { getThemeTag } from './get_theme_tag';
 import { renderTemplate } from './render_template';
 
@@ -72,14 +72,7 @@ export const bootstrapRendererFactory: BootstrapRendererFactory = ({
       regularBundlePath,
     });
 
-    const jsDependencyPaths = [
-      ...UiSharedDeps.jsDepFilenames.map(
-        (filename) => `${regularBundlePath}/kbn-ui-shared-deps/${filename}`
-      ),
-      `${regularBundlePath}/kbn-ui-shared-deps/${UiSharedDeps.jsFilename}`,
-      `${regularBundlePath}/core/core.entry.js`,
-      ...[...bundlePaths.values()].map((plugin) => plugin.bundlePath),
-    ];
+    const jsDependencyPaths = getJsDependencyPaths(regularBundlePath, bundlePaths);
 
     // These paths should align with the bundle routes configured in
     // src/optimize/bundles_route/bundles_route.ts
diff --git a/src/core/server/rendering/bootstrap/get_js_dependency_paths.test.ts b/src/core/server/rendering/bootstrap/get_js_dependency_paths.test.ts
new file mode 100644
index 0000000000000..964e64186459f
--- /dev/null
+++ b/src/core/server/rendering/bootstrap/get_js_dependency_paths.test.ts
@@ -0,0 +1,32 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { getJsDependencyPaths } from './get_js_dependency_paths';
+import type { PluginInfo } from './get_plugin_bundle_paths';
+
+describe('getJsDependencyPaths', () => {
+  it('returns the correct list of paths', () => {
+    const bundlePaths = new Map<string, PluginInfo>();
+    bundlePaths.set('plugin1', {
+      bundlePath: 'plugin1/bundle-path.js',
+      publicPath: 'plugin1/public-path',
+    });
+    bundlePaths.set('plugin2', {
+      bundlePath: 'plugin2/bundle-path.js',
+      publicPath: 'plugin2/public-path',
+    });
+
+    expect(getJsDependencyPaths('/regular-bundle-path', bundlePaths)).toEqual([
+      '/regular-bundle-path/kbn-ui-shared-deps/kbn-ui-shared-deps.@elastic.js',
+      '/regular-bundle-path/kbn-ui-shared-deps/kbn-ui-shared-deps.js',
+      '/regular-bundle-path/core/core.entry.js',
+      'plugin1/bundle-path.js',
+      'plugin2/bundle-path.js',
+    ]);
+  });
+});
diff --git a/src/core/server/rendering/bootstrap/get_js_dependency_paths.ts b/src/core/server/rendering/bootstrap/get_js_dependency_paths.ts
new file mode 100644
index 0000000000000..72c7b84fbee2e
--- /dev/null
+++ b/src/core/server/rendering/bootstrap/get_js_dependency_paths.ts
@@ -0,0 +1,24 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import * as UiSharedDeps from '@kbn/ui-shared-deps';
+import type { PluginInfo } from './get_plugin_bundle_paths';
+
+export const getJsDependencyPaths = (
+  regularBundlePath: string,
+  bundlePaths: Map<string, PluginInfo>
+) => {
+  return [
+    ...UiSharedDeps.jsDepFilenames.map(
+      (filename) => `${regularBundlePath}/kbn-ui-shared-deps/${filename}`
+    ),
+    `${regularBundlePath}/kbn-ui-shared-deps/${UiSharedDeps.jsFilename}`,
+    `${regularBundlePath}/core/core.entry.js`,
+    ...[...bundlePaths.values()].map((plugin) => plugin.bundlePath),
+  ];
+};
diff --git a/src/core/server/rendering/bootstrap/get_plugin_bundle_paths.ts b/src/core/server/rendering/bootstrap/get_plugin_bundle_paths.ts
index a42f7b9974f57..c8291b2720a92 100644
--- a/src/core/server/rendering/bootstrap/get_plugin_bundle_paths.ts
+++ b/src/core/server/rendering/bootstrap/get_plugin_bundle_paths.ts
@@ -8,7 +8,7 @@
 
 import { UiPlugins } from '../../plugins';
 
-interface PluginInfo {
+export interface PluginInfo {
   publicPath: string;
   bundlePath: string;
 }