Hexagonal Separation
A competent developer establishes clear, goal-oriented modular boundaries. Adopt hexagonal architecture principles (Ports and Adapters) to isolate your application logic completely. The application core should expose abstract interfaces (Ports) for all external concerns—databases, message queues, APIs, and UIs. External drivers implement concrete integrations (Adapters) to satisfy those interfaces.
This goal-oriented separation ensures that changing frameworks or third-party service providers doesn’t risk breaking your application core.
Discussion: When databases, UI engines, or message brokers need to change, a well-isolated application core remains untouched. Decoupling turns potentially catastrophic rewrites into routine, isolated updates.