diff --git a/.changeset/popular-bobcats-occur.md b/.changeset/popular-bobcats-occur.md
new file mode 100644
index 0000000000..bdf311029b
--- /dev/null
+++ b/.changeset/popular-bobcats-occur.md
@@ -0,0 +1,7 @@
+---
+'@backstage/plugin-app-backend': minor
+---
+
+**BREAKING**: Removed support for the old backend system.
+
+As part of this change the plugin export from `/alpha` as been removed. If you are currently importing `@backstage/plugin-app-backend/alpha`, please update your import to `@backstage/plugin-app-backend`.
diff --git a/packages/backend-legacy/package.json b/packages/backend-legacy/package.json
index a740f80004..719f3fbcef 100644
--- a/packages/backend-legacy/package.json
+++ b/packages/backend-legacy/package.json
@@ -35,7 +35,6 @@
     "@backstage/catalog-model": "workspace:^",
     "@backstage/config": "workspace:^",
     "@backstage/integration": "workspace:^",
-    "@backstage/plugin-app-backend": "workspace:^",
     "@backstage/plugin-auth-backend": "workspace:^",
     "@backstage/plugin-auth-node": "workspace:^",
     "@backstage/plugin-catalog-backend": "workspace:^",
@@ -67,7 +66,6 @@
     "azure-devops-node-api": "^14.0.0",
     "better-sqlite3": "^11.0.0",
     "dockerode": "^4.0.0",
-    "example-app": "link:../app",
     "express": "^4.17.1",
     "express-prom-bundle": "^7.0.0",
     "express-promise-router": "^4.1.0",
diff --git a/packages/backend-legacy/src/index.ts b/packages/backend-legacy/src/index.ts
index 4632cddc56..507a1f2aee 100644
--- a/packages/backend-legacy/src/index.ts
+++ b/packages/backend-legacy/src/index.ts
@@ -44,7 +44,6 @@ import kubernetes from './plugins/kubernetes';
 import scaffolder from './plugins/scaffolder';
 import search from './plugins/search';
 import techdocs from './plugins/techdocs';
-import app from './plugins/app';
 import permission from './plugins/permission';
 import { PluginEnvironment } from './types';
 import { ServerPermissionClient } from '@backstage/plugin-permission-node';
@@ -131,7 +130,6 @@ async function main() {
   const searchEnv = useHotMemoize(module, () => createEnv('search'));
   const techdocsEnv = useHotMemoize(module, () => createEnv('techdocs'));
   const kubernetesEnv = useHotMemoize(module, () => createEnv('kubernetes'));
-  const appEnv = useHotMemoize(module, () => createEnv('app'));
   const permissionEnv = useHotMemoize(module, () => createEnv('permission'));
   const eventsEnv = useHotMemoize(module, () => createEnv('events'));
 
@@ -150,8 +148,7 @@ async function main() {
     .loadConfig(config)
     .addRouter('', await healthcheck(healthcheckEnv))
     .addRouter('', metricsHandler())
-    .addRouter('/api', apiRouter)
-    .addRouter('', await app(appEnv));
+    .addRouter('/api', apiRouter);
 
   await service.start().catch(err => {
     logger.error(err);
diff --git a/packages/backend-legacy/src/plugins/app.ts b/packages/backend-legacy/src/plugins/app.ts
deleted file mode 100644
index 03d1ad95e7..0000000000
--- a/packages/backend-legacy/src/plugins/app.ts
+++ /dev/null
@@ -1,30 +0,0 @@
-/*
- * Copyright 2020 The Backstage Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import { createRouter } from '@backstage/plugin-app-backend';
-import { Router } from 'express';
-import { PluginEnvironment } from '../types';
-
-export default async function createPlugin(
-  env: PluginEnvironment,
-): Promise<Router> {
-  return await createRouter({
-    logger: env.logger,
-    config: env.config,
-    database: env.database,
-    appPackageName: 'example-app',
-  });
-}
diff --git a/plugins/app-backend/dev/index.ts b/plugins/app-backend/dev/index.ts
index 03f1931337..bb4368d842 100644
--- a/plugins/app-backend/dev/index.ts
+++ b/plugins/app-backend/dev/index.ts
@@ -23,5 +23,5 @@ backend.add(
     data: { app: { packageName: 'example-app' } },
   }),
 );
-backend.add(import('../src/alpha'));
+backend.add(import('../src'));
 backend.start();
diff --git a/plugins/app-backend/package.json b/plugins/app-backend/package.json
index a5e97727fc..cbb4bd078d 100644
--- a/plugins/app-backend/package.json
+++ b/plugins/app-backend/package.json
@@ -26,16 +26,12 @@
   "license": "Apache-2.0",
   "exports": {
     ".": "./src/index.ts",
-    "./alpha": "./src/alpha.ts",
     "./package.json": "./package.json"
   },
   "main": "src/index.ts",
   "types": "src/index.ts",
   "typesVersions": {
     "*": {
-      "alpha": [
-        "src/alpha.ts"
-      ],
       "package.json": [
         "package.json"
       ]
@@ -64,7 +60,6 @@
     "@backstage/plugin-app-node": "workspace:^",
     "@backstage/plugin-auth-node": "workspace:^",
     "@backstage/types": "workspace:^",
-    "@types/express": "^4.17.6",
     "express": "^4.17.1",
     "express-promise-router": "^4.1.0",
     "fs-extra": "^11.2.0",
@@ -81,6 +76,7 @@
     "@backstage/backend-test-utils": "workspace:^",
     "@backstage/cli": "workspace:^",
     "@backstage/types": "workspace:^",
+    "@types/express": "^4.17.6",
     "@types/supertest": "^2.0.8",
     "supertest": "^7.0.0"
   },
diff --git a/plugins/app-backend/report-alpha.api.md b/plugins/app-backend/report-alpha.api.md
deleted file mode 100644
index 78c4b97232..0000000000
--- a/plugins/app-backend/report-alpha.api.md
+++ /dev/null
@@ -1,13 +0,0 @@
-## API Report File for "@backstage/plugin-app-backend"
-
-> Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
-
-```ts
-import { BackendFeature } from '@backstage/backend-plugin-api';
-
-// @alpha (undocumented)
-const _appPlugin: BackendFeature;
-export default _appPlugin;
-
-// (No @packageDocumentation comment for this package)
-```
diff --git a/plugins/app-backend/report.api.md b/plugins/app-backend/report.api.md
index 35e7ea383d..08776e8fa9 100644
--- a/plugins/app-backend/report.api.md
+++ b/plugins/app-backend/report.api.md
@@ -3,36 +3,9 @@
 > Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
 
 ```ts
-import { AuthService } from '@backstage/backend-plugin-api';
 import { BackendFeature } from '@backstage/backend-plugin-api';
-import { ConfigSchema } from '@backstage/config-loader';
-import { DatabaseService } from '@backstage/backend-plugin-api';
-import express from 'express';
-import { HttpAuthService } from '@backstage/backend-plugin-api';
-import { LoggerService } from '@backstage/backend-plugin-api';
-import { RootConfigService } from '@backstage/backend-plugin-api';
 
 // @public
 const appPlugin: BackendFeature;
 export default appPlugin;
-
-// @public @deprecated (undocumented)
-export function createRouter(options: RouterOptions): Promise<express.Router>;
-
-// @public @deprecated (undocumented)
-export interface RouterOptions {
-  appPackageName: string;
-  // (undocumented)
-  auth?: AuthService;
-  // (undocumented)
-  config: RootConfigService;
-  database?: DatabaseService;
-  disableConfigInjection?: boolean;
-  // (undocumented)
-  httpAuth?: HttpAuthService;
-  // (undocumented)
-  logger: LoggerService;
-  schema?: ConfigSchema;
-  staticFallbackHandler?: express.Handler;
-}
 ```
diff --git a/plugins/app-backend/src/alpha.ts b/plugins/app-backend/src/alpha.ts
deleted file mode 100644
index eb661bc295..0000000000
--- a/plugins/app-backend/src/alpha.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright 2023 The Backstage Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import { appPlugin } from './service/appPlugin';
-
-/** @alpha */
-const _appPlugin = appPlugin;
-export default _appPlugin;
diff --git a/plugins/app-backend/src/service/router.test.ts b/plugins/app-backend/src/service/router.test.ts
index cdb150e06c..12b471c1f2 100644
--- a/plugins/app-backend/src/service/router.test.ts
+++ b/plugins/app-backend/src/service/router.test.ts
@@ -14,14 +14,14 @@
  * limitations under the License.
  */
 
-import { AppConfig, ConfigReader } from '@backstage/config';
+import { AppConfig } from '@backstage/config';
 import express from 'express';
 import Router from 'express-promise-router';
 import { resolve as resolvePath } from 'path';
 import request from 'supertest';
 import { createRouter } from './router';
 import { loadConfigSchema } from '@backstage/config-loader';
-import { mockServices } from '@backstage/backend-test-utils';
+import { mockServices, TestDatabases } from '@backstage/backend-test-utils';
 
 jest.mock('../lib/config', () => ({
   injectConfig: jest.fn(),
@@ -34,12 +34,24 @@ global.__non_webpack_require__ = {
 };
 
 describe('createRouter', () => {
+  const databases = TestDatabases.create({ ids: ['SQLITE_3'] });
+
   let app: express.Express;
 
   beforeAll(async () => {
+    const knex = databases.init('SQLITE_3');
     const router = await createRouter({
       logger: mockServices.logger.mock(),
-      config: new ConfigReader({}),
+      database: mockServices.database.mock({
+        getClient: () => knex,
+      }),
+      auth: mockServices.auth(),
+      httpAuth: mockServices.httpAuth(),
+      config: mockServices.rootConfig({
+        data: {
+          app: { disableStaticFallbackCache: true },
+        },
+      }),
       appPackageName: 'example-app',
     });
     app = express().use(router);
@@ -97,7 +109,14 @@ describe('createRouter with static fallback handler', () => {
 
     const router = await createRouter({
       logger: mockServices.logger.mock(),
-      config: new ConfigReader({}),
+      database: mockServices.database.mock(),
+      auth: mockServices.auth(),
+      httpAuth: mockServices.httpAuth(),
+      config: mockServices.rootConfig({
+        data: {
+          app: { disableStaticFallbackCache: true },
+        },
+      }),
       appPackageName: 'example-app',
       staticFallbackHandler,
     });
@@ -132,8 +151,16 @@ describe('createRouter config schema test', () => {
   it('uses an external schema', async () => {
     await createRouter({
       logger: mockServices.logger.mock(),
-      config: new ConfigReader({
-        test: 'value',
+      database: mockServices.database.mock(),
+      auth: mockServices.auth(),
+      httpAuth: mockServices.httpAuth(),
+      config: mockServices.rootConfig({
+        data: {
+          app: {
+            disableStaticFallbackCache: true,
+          },
+          test: 'value',
+        },
       }),
       appPackageName: 'example-app',
       schema: await loadConfigSchema({
@@ -173,8 +200,16 @@ describe('createRouter config schema test', () => {
   it('uses no external schema', async () => {
     await createRouter({
       logger: mockServices.logger.mock(),
-      config: new ConfigReader({
-        test: 'value',
+      database: mockServices.database.mock(),
+      auth: mockServices.auth(),
+      httpAuth: mockServices.httpAuth(),
+      config: mockServices.rootConfig({
+        data: {
+          app: {
+            disableStaticFallbackCache: true,
+          },
+          test: 'value',
+        },
       }),
       appPackageName: 'example-app',
     });
diff --git a/plugins/app-backend/src/service/router.ts b/plugins/app-backend/src/service/router.ts
index 4926383638..cf2ad886d7 100644
--- a/plugins/app-backend/src/service/router.ts
+++ b/plugins/app-backend/src/service/router.ts
@@ -19,7 +19,7 @@ import {
   resolvePackagePath,
   RootConfigService,
 } from '@backstage/backend-plugin-api';
-import { AppConfig } from '@backstage/config';
+import type { AppConfig } from '@backstage/config';
 import helmet from 'helmet';
 import express, { Request, Response } from 'express';
 import Router from 'express-promise-router';
@@ -35,7 +35,7 @@ import {
   CACHE_CONTROL_NO_CACHE,
   CACHE_CONTROL_REVALIDATE_CACHE,
 } from '../lib/headers';
-import { ConfigSchema } from '@backstage/config-loader';
+import type { ConfigSchema } from '@backstage/config-loader';
 import {
   AuthService,
   HttpAuthService,
@@ -48,21 +48,20 @@ import { injectConfig, readFrontendConfig } from '../lib/config';
 type Mime = { lookup(arg0: string): string };
 
 /**
- * @public
- * @deprecated Please migrate to the new backend system as this will be removed in the future.
+ * @internal
  */
 export interface RouterOptions {
   config: RootConfigService;
   logger: LoggerService;
-  auth?: AuthService;
-  httpAuth?: HttpAuthService;
+  auth: AuthService;
+  httpAuth: HttpAuthService;
 
   /**
    * If a database is provided it will be used to cache previously deployed static assets.
    *
    * This is a built-in alternative to using a `staticFallbackHandler`.
    */
-  database?: DatabaseService;
+  database: DatabaseService;
 
   /**
    * The name of the app package that content should be served from. The same app package should be
@@ -86,17 +85,6 @@ export interface RouterOptions {
    */
   staticFallbackHandler?: express.Handler;
 
-  /**
-   * Disables the configuration injection. This can be useful if you're running in an environment
-   * with a read-only filesystem, or for some other reason don't want configuration to be injected.
-   *
-   * Note that this will cause the configuration used when building the app bundle to be used, unless
-   * a separate configuration loading strategy is set up.
-   *
-   * This also disables configuration injection though `APP_CONFIG_` environment variables.
-   */
-  disableConfigInjection?: boolean;
-
   /**
    *
    * Provides a ConfigSchema.
@@ -106,8 +94,7 @@ export interface RouterOptions {
 }
 
 /**
- * @public
- * @deprecated Please migrate to the new backend system as this will be removed in the future.
+ * @internal
  */
 export async function createRouter(
   options: RouterOptions,
@@ -122,9 +109,9 @@ export async function createRouter(
     schema,
   } = options;
 
-  const disableConfigInjection =
-    options.disableConfigInjection ??
-    config.getOptionalBoolean('app.disableConfigInjection');
+  const disableConfigInjection = config.getOptionalBoolean(
+    'app.disableConfigInjection',
+  );
   const disableStaticFallbackCache = config.getOptionalBoolean(
     'app.disableStaticFallbackCache',
   );
@@ -153,13 +140,12 @@ export async function createRouter(
         schema,
       });
 
-  const assetStore =
-    options.database && !disableStaticFallbackCache
-      ? await StaticAssetsStore.create({
-          logger,
-          database: options.database,
-        })
-      : undefined;
+  const assetStore = !disableStaticFallbackCache
+    ? await StaticAssetsStore.create({
+        logger,
+        database: options.database,
+      })
+    : undefined;
 
   const router = Router();
 
@@ -167,10 +153,9 @@ export async function createRouter(
 
   const publicDistDir = resolvePath(appDistDir, 'public');
 
-  const enablePublicEntryPoint =
-    (await fs.pathExists(publicDistDir)) && auth && httpAuth;
+  const enablePublicEntryPoint = await fs.pathExists(publicDistDir);
 
-  if (enablePublicEntryPoint && auth && httpAuth) {
+  if (enablePublicEntryPoint) {
     logger.info(
       `App is running in protected mode, serving public content from ${publicDistDir}`,
     );
diff --git a/yarn.lock b/yarn.lock
index 378e56eb4a..0ab2120a81 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -28814,12 +28814,6 @@ __metadata:
   languageName: node
   linkType: soft
 
-"example-app@link:../app::locator=example-backend-legacy%40workspace%3Apackages%2Fbackend-legacy":
-  version: 0.0.0-use.local
-  resolution: "example-app@link:../app::locator=example-backend-legacy%40workspace%3Apackages%2Fbackend-legacy"
-  languageName: node
-  linkType: soft
-
 "example-app@workspace:packages/app":
   version: 0.0.0-use.local
   resolution: "example-app@workspace:packages/app"
@@ -28898,7 +28892,6 @@ __metadata:
     "@backstage/cli": "workspace:^"
     "@backstage/config": "workspace:^"
     "@backstage/integration": "workspace:^"
-    "@backstage/plugin-app-backend": "workspace:^"
     "@backstage/plugin-auth-backend": "workspace:^"
     "@backstage/plugin-auth-node": "workspace:^"
     "@backstage/plugin-catalog-backend": "workspace:^"
@@ -28934,7 +28927,6 @@ __metadata:
     azure-devops-node-api: ^14.0.0
     better-sqlite3: ^11.0.0
     dockerode: ^4.0.0
-    example-app: "link:../app"
     express: ^4.17.1
     express-prom-bundle: ^7.0.0
     express-promise-router: ^4.1.0