clean-architecture

To isolate business logic in clean architecture, you enforce an inward dependency direction, keeping core domain rules separate from infrastructure by defining explicit ports and adapters. This ensures framework isolation and testable boundaries.

Dependency inversion in use-case isolation means inner layers define stable abstractions, allowing outer infrastructure to implement them. This keeps the domain free of delivery mechanics and supports scalable monoliths or modular microservices.

Yes, you can use clean architecture to restructure legacy code by applying boundary definitions and interface ownership. This helps untangle accidental dependencies and separate core business rules from infrastructure frameworks.

You define entities and ports by identifying core domain concepts first, then establishing explicit boundaries for use cases. This approach supports DDD and CQRS by ensuring stable abstractions and independent, testable layers.

The best way to organize testable layers is starting with core domain concepts, defining use cases and ports, then isolating infrastructure behind adapters. This clean architecture approach lets you vary delivery mechanisms without touching business logic.