Why NestJS for ERP?

NestJS provides a solid foundation for building scalable server-side applications. Its dependency injection system and modular architecture fit well with enterprise needs.

Project Structure

src/
├── modules/
│   ├── orders/
│   ├── inventory/
│   ├── customers/
│   └── reporting/
├── shared/
│   ├── guards/
│   ├── interceptors/
│   └── decorators/
└── main.ts

Organizing code by feature modules keeps related code together and makes navigation intuitive.

Handling Business Logic

Business rules often span multiple entities. I used domain services to coordinate complex operations.

@Injectable()
export class OrderProcessingService {
  constructor(
    private orderRepo: OrderRepository,
    private inventoryService: InventoryService,
    private notificationService: NotificationService,
  ) {}

  async processOrder(orderId: string): Promise<void> {
    // Transaction-like operation
  }
}

API Design

RESTful endpoints with proper versioning help maintain backwards compatibility.

@Controller('api/v1/orders')
export class OrdersController {}

Caching Strategy

For frequently accessed data, I implemented Redis caching with intelligent invalidation.

Error Handling

Consistent error responses across the API make client integration smoother.

Performance Monitoring

Logging and metrics helped identify bottlenecks in production.