Clean Architecture

Clean Architecture

Overview

Keep the core domain and use cases at the center. Frameworks, databases, and UI are details that depend inward, not the other way around.

When to Use

• Growing applications that need clearer boundaries
• Reducing coupling to frameworks or infrastructure
• Improving testability of business logic

Core Ideas

• Dependency rule: source code dependencies point inward
• Entities and use cases should not depend on UI, database, or external services
• Interfaces (ports) define what the core needs; adapters implement them
• Test business rules without spinning up frameworks or databases

Practical Guidance

• Start simple; don’t over-layer small applications
• Enforce boundaries with package/module structure and code review
• Be pragmatic — pure forms of the architecture are less important than clear separation of concerns

Verification

• Core business logic can be tested in isolation
• Framework and infrastructure changes do not force widespread domain changes