Hexagonal Architecture - Intro

#hexagonal #architecture

Understanding Hexagonal Architecture (Ports & Adapters)

Sample Code with README:
https://github.com/rajkundalia/hexagonal-architecture-demo — This would explain everything in detail.

My Readings

The paper on Hexagonal Architecture by Alistair Cockburn
https://alistair.cockburn.us/hexagonal-architecture
This is very intuitive
https://scalastic.io/en/hexagonal-architecture/
This gave me a very good idea at the beginning
https://medium.com/ssense-tech/hexagonal-architecture-there-are-always-two-sides-to-every-story-bc0780ed7d9c

I read them in order: 3 → 1 → 2 (found later).

If you want to skip reading the big pages, the below mentioned summary from LLM and sample code should suffice too.

What is Hexagonal Architecture?

Hexagonal architecture, also known as ports and adapters architecture, is a software design pattern that aims to create loosely coupled systems by separating the core business logic (the “application core”) from external concerns such as databases, user interfaces, and third-party services.

This separation is achieved through:

Ports: Interfaces that define how the core interacts with the outside world.
Adapters: Components that implement these interfaces to connect with specific technologies or protocols.

Key Aspects

Isolation of Business Logic:
The core business logic is placed at the center and is independent of external systems. This makes it easier to test and maintain.
Ports:
Define communication interfaces:
- Inbound Ports: For receiving requests (e.g., from UI or API)
- Outbound Ports: For sending data to external systems (e.g., databases)
Adapters:

Implement the ports, translating between the application core and technologies like HTTP, databases, message queues, etc.
Decoupling and Flexibility:

Swap out external components (e.g., change the DB or UI) without modifying the core.
Testability:

Core logic can be tested independently, using mocks or test doubles.