Architecting NestJS Modules

When to use

• Adding a new feature module
• Splitting a monolithic AppModule
• Fixing tangled imports between modules

Core rules

1. Feature modules own their domain, application, infrastructure layers
2. Providers default to Scope.DEFAULT (singleton), use Scope.REQUEST only when needed
3. Export only what other modules need (don't export everything)
4. Dynamic modules for configurable features (database, cache)
5. No cross-feature imports; use shared contracts

Reference shape (TypeScript)