How Clean Architecture Can Be Used to Build More Testable, Maintainable, and Evolvable Applications

What is Clean Architecture?

Clean Architecture is an architectural style that separates the concerns of your application into different layers. This makes it easier to test, maintain, and evolve your code.

The four layers of Clean Architecture are:

• The Domain Layer contains the core business logic of your application. This layer should be independent of any other layers, so that it can be reused in other applications.
• The Application Layer contains the code that orchestrates the flow of data between the Domain Layer and the Infrastructure Layer. This layer is responsible for calling the appropriate methods in the Domain Layer and passing the results back to the user.
• The Infrastructure Layer contains the code that interacts with the outside world. This layer is responsible for things like database access, web services, and user interfaces.
• The Presentation Layer is the user interface of your application. This layer is responsible for displaying data to the user and collecting input from the user.

Why should you use Clean Architecture?

There are many reasons why you should use Clean Architecture, including:

• Testability. Clean Architecture makes it easier to write unit tests for your code. This is because the Domain Layer is independent of any other layers, so you can test it in isolation.
• Maintainability. Clean Architecture makes it easier to maintain your code. This is because the different layers are well-defined and isolated, so you can make changes to one layer without affecting the others.
• Evolvability. Clean Architecture makes it easier to evolve your code. This is because the different layers are loosely coupled, so you can add new features or change existing features without affecting the rest of the application.

Enterprise examples of Clean Architecture

There are many enterprise applications that use Clean Architecture, including:

• The Stack Overflow website uses Clean Architecture to separate the concerns of the application into different layers. This makes it easier to test, maintain, and evolve the code.
• The Google Maps API uses Clean Architecture to provide a consistent and reliable way for developers to access Google Maps data.
• The Microsoft Azure cloud platform uses Clean Architecture to provide a scalable and reliable platform for hosting applications.
• The Netflix streaming service uses Clean Architecture to separate the concerns of the application into different layers. This makes it easier to test, maintain, and evolve the code.
• The Amazon e-commerce platform uses Clean Architecture to provide a scalable and reliable platform for online shopping.
• The Google search engine uses Clean Architecture to provide a fast and accurate search experience.
• The Microsoft Office suite uses Clean Architecture to provide a powerful and user-friendly productivity suite.
• The Salesforce CRM platform uses Clean Architecture to provide a comprehensive and flexible customer relationship management solution.

Pros and cons of Clean Architecture

Clean Architecture has many advantages, but it also has some disadvantages.

Advantages

• Testability. Clean Architecture makes it easier to write unit tests for your code. This is because the Domain Layer is independent of any other layers, so you can test it in isolation.
• Maintainability. Clean Architecture makes it easier to maintain your code. This is because the different layers are well-defined and isolated, so you can make changes to one layer without affecting the others.
• Evolvability. Clean Architecture makes it easier to evolve your code. This is because the different layers are loosely coupled, so you can add new features or change existing features without affecting the rest of the application.

Disadvantages

• Complexity. Clean Architecture can be more complex than other architectural styles. This is because it requires you to think carefully about the different layers of your application and how they interact with each other.
• Overhead. Clean Architecture can add some overhead to your application. This is because the different layers need to be communicated with each other, which can add some complexity and performance overhead.

Microservices Example

Based on the idea of clean architecture, I have created a complete end to end Application covering following topics. In this series, you guys will be implementing below E-commerce architecture right from the blank slate.

• Creating .NET Core Microservices using Clean Architecture. This course will teach you how to apply Clean Architecture to .NET Core microservices development. You will learn how to design your microservices in a way that makes them testable, maintainable, and evolvable. By the end of this course, you will be able to build microservices that are easy to test, debug, and extend.
• Securing Microservices using Identity Server 4. This course teaches you how to secure your .NET Core Microservices using Identity Server 4 and apply all the best practices between microservices communication.
• Implementing Cross-Cutting Concerns for ASP.NET Microservices. This course teaches you how to implement cross-cutting concerns, such as logging, monitoring, and security, in your .NET Core Microservices. In this course, you will also see, how to integrate ELK stack and write custom co-relation id generator.
• Versioning Microservices. This course teaches you how to version your .NET Core Microservices so that you can safely deploy changes to production.
• Building Ecommerce Angular Application. This course will show you how to build an e-commerce application using Angular and .NET Core microservices. The Angular application will be the presentation layer that consumes the microservices API.
• Deploying Microservices to Kubernetes and AKS. This course will show you how to deploy your .NET Core microservices to Kubernetes and Azure Kubernetes Service (AKS). You will also learn how to enable service mesh using the Istio framework.
• Docker for .NET and Angular Developers. Docker is a key prerequisite for any Microservices course. If you are new to Docker and Kubernetes, this course will provide you with the foundation you need to get started.

Conclusion

Clean Architecture is a powerful architectural style that can help you to write more testable, maintainable, and evolvable code. However, it is important to be aware of the complexity and overhead that Clean Architecture can add to your application.

Comparison with other architectures

Clean Architecture is often compared to other architectural styles, such as MVC and MVVM. MVC and MVVM are both architectural styles that separate the concerns of your application into different layers. However, Clean Architecture goes a step further by separating the concerns of your application into different domains. This makes it even easier to test, maintain, and evolve your code.

Conclusion

Clean Architecture is a powerful architectural style that can help you to write more testable, maintainable, and evolvable code. If you are looking for an architectural style that can help you to build high-quality software, then Clean Architecture is a great option.

Originally published at My View.