260223:1415 20260223 nextJS & nestJS Best pratices

.agents/skills/nestjs-best-practices/rules/arch-feature-modules.md

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+---
+title: Organize by Feature Modules
+impact: CRITICAL
+impactDescription: "3-5x faster onboarding and development"
+tags: architecture, modules, organization
+---
+
+## Organize by Feature Modules
+
+Organize 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.
+
+**Incorrect (technical layer organization):**
+
+```typescript
+// Technical layer organization (anti-pattern)
+src/
+├── controllers/
+│   ├── users.controller.ts
+│   ├── orders.controller.ts
+│   └── products.controller.ts
+├── services/
+│   ├── users.service.ts
+│   ├── orders.service.ts
+│   └── products.service.ts
+├── entities/
+│   ├── user.entity.ts
+│   ├── order.entity.ts
+│   └── product.entity.ts
+└── app.module.ts  // Imports everything directly
+```
+
+**Correct (feature module organization):**
+
+```typescript
+// Feature module organization
+src/
+├── users/
+│   ├── dto/
+│   │   ├── create-user.dto.ts
+│   │   └── update-user.dto.ts
+│   ├── entities/
+│   │   └── user.entity.ts
+│   ├── users.controller.ts
+│   ├── users.service.ts
+│   ├── users.repository.ts
+│   └── users.module.ts
+├── orders/
+│   ├── dto/
+│   ├── entities/
+│   ├── orders.controller.ts
+│   ├── orders.service.ts
+│   └── orders.module.ts
+├── shared/
+│   ├── guards/
+│   ├── interceptors/
+│   ├── filters/
+│   └── shared.module.ts
+└── app.module.ts
+
+// users.module.ts
+@Module({
+  imports: [TypeOrmModule.forFeature([User])],
+  controllers: [UsersController],
+  providers: [UsersService, UsersRepository],
+  exports: [UsersService], // Only export what others need
+})
+export class UsersModule {}
+
+// app.module.ts
+@Module({
+  imports: [
+    ConfigModule.forRoot(),
+    TypeOrmModule.forRoot(),
+    UsersModule,
+    OrdersModule,
+    SharedModule,
+  ],
+})
+export class AppModule {}
+```
+
+Reference: [NestJS Modules](https://docs.nestjs.com/modules)