Can you explain the concept of hexagonal architecture?

Hexagonal Architecture, also known as Ports and Adapters Architecture, aims to separate the application's business logic from external systems and interfaces.

The main idea is that the business logic (core) interacts with the external world through ports (interfaces), and adapters implement these ports for specific technologies (e.g., databases, web interfaces, external services).

This allows:

• Easy replacement of external components without changing the business logic.
• Writing tests by isolating the core from external dependencies.
• Improving support and extendability of the application.

Example: in Java, you have an interface UserRepository (port), and specific implementations like UserRepositoryJdbc or UserRepositoryInMemory are adapters. The business logic only works with the interface, independent of the specific implementation.