NestJS architecture, dependency injection, validation, security, errors, testing, persistence, APIs, microservices, and deployment patterns with prioritized rule tiers and companion rule files.
99
100%
Does it follow best practices?
Impact
97%
1.12xAverage score across 2 eval scenarios
Advisory
Suggest reviewing before use
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):
// 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 directlyCorrect (feature module organization):
// 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
evals
scenario-1
scenario-2
rules