domain-driven-design

Domain-driven design is a structured approach to modeling complex business domains, keeping domain logic central and boundaries clear. Use it when you need to protect invariants and prevent infrastructure concerns from leaking into core business behavior.

To model an aggregate, define a bounded context for a core business concept, implement it as an aggregate root, enforce invariants inside it, and emit domain events. This keeps business rules framework-agnostic across TypeScript and Python implementations.

CQRS separates read and write models to optimize queries and command processing independently. Event sourcing reconstructs aggregate state by replaying event streams, providing an audit log and enabling temporal queries for complex domain logic.

Strategic design defines bounded contexts, ubiquitous language, and context boundaries to align team ownership. Tactical patterns include aggregates, entities, value objects, and repositories to encapsulate business rules within those defined boundaries.

Yes, bounded contexts isolate domain logic from persistence and infrastructure concerns. Defining clear context boundaries ensures that core business behavior remains framework-agnostic and invariants are protected within specific domain models.

Avoid domain-driven design for simple CRUD applications or domains lacking complex business rules. DDD introduces strategic and tactical overhead that is unnecessary when invariants are minimal and domain logic does not require bounded context isolation.