DDD Bounded Context Generator

DDD layered architecture separates your backend into Domain, Application, Infrastructure, and Presentation layers with unidirectional dependencies. This isolates business logic from frameworks, making your code testable and maintainable. Start by defining domain entities and value objects in a framework-agnostic domain layer, then build application services, repository implementations, and presentation adapters in upper layers.

Entities have unique identities that persist over time and encapsulate mutable state and business logic. Value objects represent immutable concepts defined by their attributes—two value objects are equal if their attributes match, regardless of identity. Both belong in your domain layer and model core business concepts without framework dependencies.

Define repository interfaces in your domain layer as contracts for persistence, then implement them in the infrastructure layer. This abstracts database details from your domain logic. Your application services depend on repository interfaces, not concrete implementations, keeping the domain layer framework-agnostic and testable.

Yes. NestJS works well with DDD when you keep your domain layer free of NestJS decorators and framework code. Place your entities, value objects, and domain services in a pure domain module, then use NestJS modules, controllers, and services in application and presentation layers to orchestrate use cases and handle HTTP concerns separately.

Create a new bounded context when a feature has distinct business rules, language, or persistence needs that would complicate an existing context. Examples include separating Club Management from User Authentication. Each bounded context owns its domain model, repositories, and application services, reducing coupling and improving maintainability.

Understand your domain's core business rules and terminology. Identify aggregate roots, entities, and value objects. Plan your layer structure and dependency flow. Set up project directories for domain, application, infrastructure, and presentation layers. Have NestJS and Prisma available if using this Skill's stack, though the domain layer remains framework-independent.