I. Overview of Software Architecture

II. Why Do We Need to Architect Applications?

• To create applications that are easy to scale and maintain

• To avoid being affected by frameworks or libraries

• To make sharing easier among team members and stakeholders

• To reduce deployment time between teams (FrontEnd/Backend/MobileApp)

III. What Is Hexagonal Architecture?

• Hexagonal Architecture (also known as the ports and adapters architecture) is a software design pattern. It focuses on building applications around business/application logic that is not affected by or dependent on any external components, interacting with them only through ports/adapters.

• Because of its independence, you can easily switch between data sources (libraries/frameworks) without impacting the business/application logic. Inputs and outputs of data sources are placed on the sides of the hexagon.

• You can implement business logic before choosing a library or framework.

• Fun fact 😃: Why a hexagon (six sides) and not another shape? The hexagon is just a name; in reality, it can be any polygon, with as many ports/adapters as needed to connect to external data sources.

IV. Why Was Hexagonal Architecture Created?

The article below highlights common issues in codebases:

As we can see:

• Code files (e.g., functions/*.php) containing mixed JavaScript, jQuery, HTML, and business logic all in one file

• Logic separated only by blank lines

• Very large files with both business and UI logic mixed together

How can we review or maintain it. In my case, no way (just kidding, I still have to fix it in real life LOL 😂)

V. Solution Provided by Hexagonal Architecture

• Separate business/application logic from other components

• With business stuff:

• With delivery stuff:

• Divide business code into Domain and Use Cases

• External components may depend on internal ones, but not the other way around

VI. Implementation

Logic code is divided into two parts:

• Domain
• models: Create necessary models, types, or interfaces
• repositories: All types and interfaces related to repositories (a repository is responsible for fetching data from various sources, such as web services, databases, or files)
• services: Responsible for interacting with models and executing related actions (e.g., a method to check if a product can be added to the cart if stock > 0)

• Infrastructufre
• http: Stores client-related objects (e.g., DTOs received from a repository)
• instances: Instances of clients and repositories, considered the system’s entry point





• repositories: Implements repositories defined in the domain

Example provided with VueJs

VII. Summary

Advantages:

✅ Organizes code around business rules, not frameworks or libraries

✅ Easy to control dependencies, only allowing inner layers to be depended on

✅ Supports testing and maintenance well

✅ Codebase is easy to extend

✅ Application is independent of technology evolution (libraries/frameworks)

✅ Reduces time spent choosing technology for the project

✅ Codebase can be shared across frontend, backend, and mobile apps

Disadvantages:

❌ More complex code organization, takes more time

VIII. References

• Netflix tech blog on hexagonal architecture

• Other online resources
• Notist
• jmgarridopaz

Thank you for reading. Happy coding 🙌