V3 DDD Architecture

Identify the distinct responsibilities in the god object, then map each to a bounded context with its own entities, value objects, services, and repositories. Extract domains in phases, starting with the most independent responsibilities like task or session management.

A microkernel is a minimal core that loads domains as pluggable modules at runtime. The kernel maintains a registry of domains, wires up domain events, and lets plugins declare dependencies on core domains like task-management and session-management.

Bounded contexts communicate through domain events published to an event bus. Each context raises events like TaskCompletedEvent, and handlers in other contexts subscribe to them, keeping domains independent and loosely coupled.

Clean architecture relies on dependency inversion, where outer layers depend on inner abstractions. Dependency injection containers wire concrete implementations like SqliteTaskRepository to domain interfaces, keeping the domain layer free of external dependencies.

DDD adds structural overhead with entities, value objects, repositories, and event handlers that may not pay off in small codebases. It is most valuable when decomposing large files with multiple responsibilities, such as a 1,400-line orchestrator.