Embracing and understanding the Hexagonal Architecture in Serverless Environments
Tags: serverless, aws, hexagonal, portadapterarchitecture
Published: 2024-01-29 12:56:03

## Introduction

In the evolving, complex, evolutionary scope of of software architecture, the needs for efficiency and scalability is perpetual. 

Considering the numerous architectural patterns, Hexagonal Architecture has emerged as a beacon for those navigating the complexities of modern application development, mandatory for every single company these days. 

Its synergy with Serverless architectures opens a new realm of possibilities. This blog describes into the fusion of Hexagonal Architecture with Serverless computing, exploring its benefits, use cases, and providing practical recommendations.


## What is Hexagonal Architecture?

Hexagonal Architecture, also known as Ports and Adapters Architecture (the preferred name choose by the author of the concept), was introduced by Alistair Cockburn. It focuses on decoupling the core logic of an application (the business logic) from external concerns like user interfaces, data storage, and external services. Sounds good, doesn't it?

In this architecture, the application core business logic is surrounded by other components as ports, which are interfaced by adapters to communicate with external elements.

## Why Merge Hexagonal Architecture with Serverless?

Serverless computing, where the cloud provider are responsible to manage the allocation and provisioning of servers, aligns perfectly with the principles of Hexagonal Architecture. This combination offers:

- Enhanced Scalability in any scale: Serverless platforms automatically scale to meet demand, making them a great fit for the flexible nature of Hexagonal Architecture, as well as other business scenarios.

- Cost Efficiency: Pay-per-use pricing models of Serverless computing align with the modular design of Hexagonal Architecture, where the cost of your business execution is just there when there are requests. If you business grows, the costs will be following your success but in much lower hate. 

- Simplified Maintenance: The Serverless model reduces operational burdens, complementing the Hexagonal Architecture's focus on isolating business logic from infrastructural concerns. Who wants to "babysitting" hardware instead of thinking about business growth?

## Benefits of Hexagonal Architecture in Serverless

Here are few of much more possible benefits of combining AWS Serverless technologies with the Hexagonal Architecture pattern.

![Benefits of Hexagonal Architecture in Serverless
](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/z20lx8zwyngg49rf4gx5.png)

1. Improved Testability and Isolation
Hexagonal Architecture simplifies testing by isolating business logic. In a serverless environment, where each function is a standalone unit, this leads to more manageable and testable codebases. You can use AWS SAM to create your business logic and test locally. [read this blog](https://aws.amazon.com/blogs/compute/getting-started-with-testing-serverless-applications/)

2. Flexibility and Adaptability
The use of adapters and ports allows for flexible integration with several Serverless services like AWS Lambda functions, Amazon API Gateway, Amazon DynamoDB, Amazon SQS and others as a input of the business or the repository of data.

3. Enhanced Domain-Driven Design
By separating core logic from external services, Hexagonal Architecture in a Serverless context encourages a stronger focus on domain-driven design, leading to more robust and coherent systems. You don't need focus your time thinking about managing APIs ou databases, you just focus on your logic. 

## Use Cases

Let's explores how a Serverless and hexagonal architecture can help you build scalable and resilient applications without the hassle of server management. Whether you're building a real-time data processing pipeline or a highly available web application, this approach can help you achieve your goals with ease

1. Event-Driven Applications
Serverless in the right tools in handling event-driven architectures in a great group of use cases. With Hexagonal Architecture, these applications can efficiently route different events (e.g., HTTP requests, file uploads) through appropriate adapters to the application core.

2. Microservices
Hexagonal Architecture complements (sometimes force us) the microservices pattern, especially in a Serverless environment. Each microservice can be independently deployed, managed, and scaled. That's beautiful.

3. API Development
Developing APIs with Serverless functions as adapters in a Hexagonal Architecture allows for clean and maintainable endpoints, with business logic (the most important think in a company) remaining unaffected by external API changes.

## Recommendations for Implementation

As defined in this [blog](https://aws.amazon.com/blogs/compute/developing-evolutionary-architecture-with-aws-lambda/), we may find some possible implementations and recommendations:


![Hexagonal Architecture](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ezui46zp3fyvl4b30akd.png)

1. Define Clear Port Interfaces
Design ports as clear interfaces for your application's core logic. This is crucial for maintaining the integrity of the architecture.

2. Choose Adapters
Select or build adapters that effectively bridge the gap between the Serverless environment and the application core. Be mindful of the serverless provider's strengths and limitations. Think about using HTTP API or messaging or event busses in your application and how theses integration will use adapters to handle the requests.

3. Emphasize on Domain-Centric Design
This is the Key. Keep the business logic at the forefront of your development process. Make sure that all external interactions are routed through the ports and adapters.

4. Monitor and Optimize
Utilize monitoring and optimization tools provided by Serverless platforms to manage function performance and costs effectively. AWS CloudWatch will be your partner to be sure that your application and your business are health. 

## Conclusion

The fusion of Hexagonal Architecture with Serverless computing offers a pathway to building scalable, flexible, and maintainable applications. 

By adhering to this pattern, organizations can harness the full potential of Serverless technology, ensuring that their applications are not only efficient but also resilient and adaptable to changing technological landscapes. 

As Serverless computing continues to evolve, the principles of Hexagonal Architecture will undoubtedly play a pivotal role in shaping future software development practices.