diff --git a/sample/10-fastify/e2e/cats.e2e-spec.ts b/sample/10-fastify/e2e/cats.e2e-spec.ts
new file mode 100644
index 00000000000..66e6d6cc615
--- /dev/null
+++ b/sample/10-fastify/e2e/cats.e2e-spec.ts
@@ -0,0 +1,85 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { INestApplication } from '@nestjs/common';
+import * as request from 'supertest';
+import { CatsModule } from '../src/cats/cats.module';
+import {
+  FastifyAdapter,
+  NestFastifyApplication,
+} from '@nestjs/platform-fastify';
+import { CreateCatDto } from '../src/cats/dto/create-cat.dto';
+import { RolesGuard } from '../src/common/guards/roles.guard';
+
+describe('CatsController (e2e)', () => {
+  let app: INestApplication;
+
+  const mockRolesGuard = { canActivate: () => true };
+
+  beforeAll(async () => {
+    const moduleFixture: TestingModule = await Test.createTestingModule({
+      imports: [CatsModule],
+    })
+      .overrideGuard(RolesGuard)
+      .useValue(mockRolesGuard)
+      .compile();
+
+    app = moduleFixture.createNestApplication<NestFastifyApplication>(
+      new FastifyAdapter(),
+    );
+
+    await app.init();
+    await app.getHttpAdapter().getInstance().ready();
+  });
+
+  afterAll(async () => {
+    await app.close();
+  });
+
+  it('/cats (GET) - initial state', () => {
+    return request(app.getHttpServer())
+      .get('/cats')
+      .expect(200)
+      .expect([]);
+  });
+
+  it('/cats (POST) - create a cat', () => {
+    const newCatDto: CreateCatDto = { name: 'Milo', age: 2, breed: 'Tabby' };
+    const expectedCat = {
+      id: 1,
+      ...newCatDto,
+    };
+
+    return request(app.getHttpServer())
+      .post('/cats')
+      .send(newCatDto)
+      .expect(201)
+      .expect(expectedCat);
+  });
+
+  it('/cats (GET) - after create', () => {
+    const expectedCat = {
+      id: 1,
+      name: 'Milo',
+      age: 2,
+      breed: 'Tabby',
+    };
+
+    return request(app.getHttpServer())
+      .get('/cats')
+      .expect(200)
+      .expect([expectedCat]);
+  });
+
+  it('/cats/:id (GET) - find one', () => {
+    const expectedCat = {
+      id: 1,
+      name: 'Milo',
+      age: 2,
+      breed: 'Tabby',
+    };
+
+    return request(app.getHttpServer())
+      .get('/cats/1')
+      .expect(200)
+      .expect(expectedCat);
+  });
+});
\ No newline at end of file
diff --git a/sample/10-fastify/e2e/jest-e2e.json b/sample/10-fastify/e2e/jest-e2e.json
new file mode 100644
index 00000000000..ac432d937e1
--- /dev/null
+++ b/sample/10-fastify/e2e/jest-e2e.json
@@ -0,0 +1,9 @@
+{
+  "moduleFileExtensions": ["js", "json", "ts"],
+  "rootDir": ".",
+  "testEnvironment": "node",
+  "testRegex": ".e2e-spec.ts$",
+  "transform": {
+    "^.+\\.(t|j)s$": "ts-jest"
+  }
+}
\ No newline at end of file
diff --git a/sample/10-fastify/jest.config.js b/sample/10-fastify/jest.config.js
new file mode 100644
index 00000000000..e4ab2b3118a
--- /dev/null
+++ b/sample/10-fastify/jest.config.js
@@ -0,0 +1,7 @@
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+  rootDir: 'src',
+  testRegex: '.*\\.spec\\.ts$',
+  moduleFileExtensions: ['js', 'json', 'ts'],
+};
\ No newline at end of file
diff --git a/sample/10-fastify/package.json b/sample/10-fastify/package.json
index 0c938371a2c..e975d5900a0 100644
--- a/sample/10-fastify/package.json
+++ b/sample/10-fastify/package.json
@@ -16,7 +16,7 @@
     "test:watch": "jest --watch",
     "test:cov": "jest --coverage",
     "test:debug": "node --inspect-brk -r tsconfig-paths/register -r ts-node/register node_modules/.bin/jest --runInBand",
-    "test:e2e": "echo 'No e2e tests implemented yet.'"
+    "test:e2e": "jest --config ./e2e/jest-e2e.json"
   },
   "dependencies": {
     "@nestjs/common": "11.1.9",
@@ -42,7 +42,7 @@
     "jest": "30.2.0",
     "prettier": "3.6.2",
     "supertest": "7.1.4",
-    "ts-jest": "29.4.5",
+    "ts-jest": "^29.4.5",
     "ts-loader": "9.5.4",
     "ts-node": "10.9.2",
     "tsconfig-paths": "4.2.0",
diff --git a/sample/10-fastify/src/cats/cats.controller.ts b/sample/10-fastify/src/cats/cats.controller.ts
index 2008e3de796..05bdb4f6e0c 100644
--- a/sample/10-fastify/src/cats/cats.controller.ts
+++ b/sample/10-fastify/src/cats/cats.controller.ts
@@ -1,32 +1,40 @@
-import { Body, Controller, Get, Param, Post, UseGuards } from '@nestjs/common';
-import { Roles } from '../common/decorators/roles.decorator';
-import { RolesGuard } from '../common/guards/roles.guard';
-import { ParseIntPipe } from '../common/pipes/parse-int.pipe';
-import { CatsService } from './cats.service';
+import {
+  Controller,
+  Get,
+  Post,
+  Body,
+  Param,
+  UseGuards,
+  NotFoundException,
+} from '@nestjs/common';
 import { CreateCatDto } from './dto/create-cat.dto';
+import { CatsService } from './cats.service';
+import { RolesGuard } from '../common/guards/roles.guard';
+import { Roles } from '../common/decorators/roles.decorator';
 import { Cat } from './interfaces/cat.interface';
 
-@UseGuards(RolesGuard)
 @Controller('cats')
+@UseGuards(RolesGuard)
 export class CatsController {
   constructor(private readonly catsService: CatsService) {}
 
   @Post()
   @Roles('admin')
-  async create(@Body() createCatDto: CreateCatDto) {
-    this.catsService.create(createCatDto);
+  create(@Body() createCatDto: CreateCatDto): Cat {
+    return this.catsService.create(createCatDto);
   }
 
   @Get()
-  async findAll(): Promise<Cat[]> {
+  findAll(): Cat[] {
     return this.catsService.findAll();
   }
 
   @Get(':id')
-  findOne(
-    @Param('id', new ParseIntPipe())
-    id: number,
-  ) {
-    // get by ID logic
+  findOne(@Param('id') id: string): Cat {
+    const cat = this.catsService.findOne(+id);
+    if (!cat) {
+      throw new NotFoundException(`Cat with ID ${id} not found`);
+    }
+    return cat;
   }
-}
+}
\ No newline at end of file
diff --git a/sample/10-fastify/src/cats/cats.service.spec.ts b/sample/10-fastify/src/cats/cats.service.spec.ts
new file mode 100644
index 00000000000..177ba5dca0e
--- /dev/null
+++ b/sample/10-fastify/src/cats/cats.service.spec.ts
@@ -0,0 +1,57 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { CatsService } from './cats.service';
+import { Cat } from './interfaces/cat.interface';
+import { CreateCatDto } from './dto/create-cat.dto';
+
+describe('CatsService', () => {
+  let service: CatsService;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [CatsService],
+    }).compile();
+
+    service = module.get<CatsService>(CatsService);
+  });
+
+  it('should be defined', () => {
+    expect(service).toBeDefined();
+  });
+
+  describe('create and findAll', () => {
+    it('should create a new cat, assign an ID, and return all cats', () => {
+      const catDto: CreateCatDto = { name: 'Milo', age: 2, breed: 'Tabby' };
+
+      const createdCat = service.create(catDto);
+
+      expect(createdCat.id).toBe(1);
+      expect(createdCat.name).toBe('Milo');
+
+      const allCats = service.findAll();
+
+      expect(allCats).toHaveLength(1);
+      expect(allCats).toEqual([createdCat]);
+
+      const catDto2: CreateCatDto = { name: 'Luna', age: 1, breed: 'Siamese' };
+      const createdCat2 = service.create(catDto2);
+      expect(createdCat2.id).toBe(2);
+    });
+  });
+
+  describe('findOne', () => {
+    it('should return a single cat by its id', () => {
+      const catDto: CreateCatDto = { name: 'Luna', age: 1, breed: 'Siamese' };
+      const createdCat = service.create(catDto);
+
+      const foundCat = service.findOne(1);
+
+      expect(foundCat).toBeDefined();
+      expect(foundCat).toEqual(createdCat);
+    });
+
+    it('should return undefined if cat is not found', () => {
+      const foundCat = service.findOne(999);
+      expect(foundCat).toBeUndefined();
+    });
+  });
+});
\ No newline at end of file
diff --git a/sample/10-fastify/src/cats/cats.service.ts b/sample/10-fastify/src/cats/cats.service.ts
index 2619cd7176d..ab265131cb7 100644
--- a/sample/10-fastify/src/cats/cats.service.ts
+++ b/sample/10-fastify/src/cats/cats.service.ts
@@ -1,15 +1,27 @@
 import { Injectable } from '@nestjs/common';
 import { Cat } from './interfaces/cat.interface';
+import { CreateCatDto } from './dto/create-cat.dto';
 
 @Injectable()
 export class CatsService {
   private readonly cats: Cat[] = [];
+  private idCounter = 1;
 
-  create(cat: Cat) {
-    this.cats.push(cat);
+  create(createCatDto: CreateCatDto): Cat {
+    const newCat: Cat = {
+      id: this.idCounter++,
+      ...createCatDto,
+    };
+
+    this.cats.push(newCat);
+    return newCat;
   }
 
   findAll(): Cat[] {
     return this.cats;
   }
-}
+
+  findOne(id: number): Cat {
+    return this.cats.find((cat) => cat.id === id);
+  }
+}
\ No newline at end of file
diff --git a/sample/10-fastify/src/cats/interfaces/cat.interface.ts b/sample/10-fastify/src/cats/interfaces/cat.interface.ts
index b3e66c4b676..1374507c67b 100644
--- a/sample/10-fastify/src/cats/interfaces/cat.interface.ts
+++ b/sample/10-fastify/src/cats/interfaces/cat.interface.ts
@@ -1,4 +1,5 @@
 export interface Cat {
+  readonly id: number;
   readonly name: string;
   readonly age: number;
   readonly breed: string;