What is clean architecture? Why is it needed?

Clean architecture is an approach to software design that separates the system into layers with clear dependencies directed inward. The main idea is to separate business logic from implementation details (such as UI, databases, external services).

Why it is needed:

• Ensures independence of business logic from frameworks and technologies
• Simplifies testing and maintenance of code
• Allows easy replacement of external components without affecting the core of the application

Main layers:

• Entities — business rules
• Use Cases — usage scenarios
• Interface Adapters — data transformation for external systems
• Frameworks & Drivers — implementation details (DB, UI)

This approach helps create flexible and scalable applications.