Hexagonal Architecture: Architecture Pattern

Hexagonal Architecture, introduced by Alistair Cockburn, is centered around the principle of separating the core business logic of an application from external concerns such as user interfaces, databases, and external services. It achieves this separation through the concept of “ports” and “adapters.”

  1. Ports: These are interfaces that define the contract between the application’s core business logic and the external components. Ports represent the inputs and outputs of the system, encapsulating the operations that the core logic should perform. Since ports provide an interface for external components, the core business logic is now agnostic of the external components creating a clear separation of concern.
  2. Adapters: Adapters implement the ports, bridging the gap between the core business logic and the external systems. They are responsible for translating external input into a format that the core logic can process and vice versa.

Advantages of Hexagonal Architecture:

  1. Modularity and Maintainability: Hexagonal Architecture encourages the creation of well-defined modules, making it easier to isolate changes and maintain different parts of the application independently.
  2. Testability: By separating the core logic from external dependencies, testing becomes more straightforward. Mocking and stubbing external services or UI components becomes seamless, facilitating unit testing and ensuring higher code quality.
  3. Flexibility: Hexagonal Architecture enables flexibility in choosing the technologies and frameworks for the external components. Changes in these external components have minimal impact on the core business logic.
  4. Clean Architecture: The architecture enforces a clear boundary between the application’s core and its interactions with the external world, resulting in a clean and organized codebase.

Disadvantages of Hexagonal Architecture:

  1. Increased Complexity: The introduction of ports and adapters can lead to increased complexity, especially in smaller projects where the benefits might not outweigh the added cognitive load.
  2. Initial Development Time: Setting up the initial structure of Hexagonal Architecture demands careful planning and design, which could extend the development time.
  3. Higher Cost of Extensibility



Pratik Pandey - https://pratikpandey.substack.com

Senior Engineer with experience in designing and architecting large scale distributed systems.