1---
2title: Organize by Feature Modules
3impact: CRITICAL
4impactDescription: "3-5x faster onboarding and development"
5tags: architecture, modules, organization
6---
7 
8## Organize by Feature Modules
9 
10Organize your application into feature modules that encapsulate related functionality. Each feature module should be self-contained with its own controllers, services, entities, and DTOs. Avoid organizing by technical layer (all controllers together, all services together). This enables 3-5x faster onboarding and feature development.
11 
12**Incorrect (technical layer organization):**
13 
14```typescript
15// Technical layer organization (anti-pattern)
16src/
17├── controllers/
18│   ├── users.controller.ts
19│   ├── orders.controller.ts
20│   └── products.controller.ts
21├── services/
22│   ├── users.service.ts
23│   ├── orders.service.ts
24│   └── products.service.ts
25├── entities/
26│   ├── user.entity.ts
27│   ├── order.entity.ts
28│   └── product.entity.ts
29└── app.module.ts  // Imports everything directly
30```
31 
32**Correct (feature module organization):**
33 
34```typescript
35// Feature module organization
36src/
37├── users/
38│   ├── dto/
39│   │   ├── create-user.dto.ts
40│   │   └── update-user.dto.ts
41│   ├── entities/
42│   │   └── user.entity.ts
43│   ├── users.controller.ts
44│   ├── users.service.ts
45│   ├── users.repository.ts
46│   └── users.module.ts
47├── orders/
48│   ├── dto/
49│   ├── entities/
50│   ├── orders.controller.ts
51│   ├── orders.service.ts
52│   └── orders.module.ts
53├── shared/
54│   ├── guards/
55│   ├── interceptors/
56│   ├── filters/
57│   └── shared.module.ts
58└── app.module.ts
59 
60// users.module.ts
61@Module({
62  imports: [TypeOrmModule.forFeature([User])],
63  controllers: [UsersController],
64  providers: [UsersService, UsersRepository],
65  exports: [UsersService], // Only export what others need
66})
67export class UsersModule {}
68 
69// app.module.ts
70@Module({
71  imports: [
72    ConfigModule.forRoot(),
73    TypeOrmModule.forRoot(),
74    UsersModule,
75    OrdersModule,
76    SharedModule,
77  ],
78})
79export class AppModule {}
80```
81 
82Reference: [NestJS Modules](https://docs.nestjs.com/modules)
83