Can you explain the principles of hexagonal architecture and its main components?

Hexagonal architecture (or Ports and Adapters) is a software design approach that separates business logic from external systems and interfaces. The main idea is to make the core of the application independent of UI, databases, external services, and other implementation details.

Main components:

• Core (Domain) — business logic and rules that do not depend on external technologies.
• Ports — abstract interfaces through which the core interacts with the outside world.
• Adapters — concrete implementations of ports, for example, for working with databases, UI, external APIs.

This allows easy replacement of external components without changing business logic and simplifies testing, as the core can be tested independently of the infrastructure.