NestJS Development Patterns Production-grade NestJS patterns for modular TypeScript backends. When to Activate - Building NestJS APIs or services - Structuring modules, controllers, and providers - Adding DTO validation, guards, interceptors, or exception filters - Configuring environment-aware settings and database integrations - Testing NestJS units or HTTP endpoints Project Structure - Keep domain code inside feature modules. - Put cross-cutting filters, decorators, guards, and interceptors in . - Keep DTOs close to the module that owns them. Bootstrap and Global Validation - Always enable…