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Clean Architecture in ASP.NET Core

Jan 15, 2023 | C#, .NET

Introduction to Clean Architecture

Clean Architecture is a software design paradigm that focuses on the separation of concerns and the maintainability of code. It has become increasingly popular in recent years due to its ability to improve the quality of software applications by enforcing modularity, testability, and scalability. In this article, we’ll dive into the world of Clean Architecture and learn how it can be applied to ASP.NET Core applications.

Why Clean Architecture in ASP.NET Core?

ASP.NET Core is a versatile and high-performance framework for building modern web applications. With its flexibility, developers can choose different architectural patterns to suit their specific needs. Clean Architecture is one such pattern that perfectly complements the ASP.NET Core framework.

Benefits of Clean Architecture

  • Modularity: Clean Architecture encourages the separation of code into independent modules, making it easier to manage, modify, and extend.
  • Testability: By isolating the different parts of the application, testing becomes much more manageable and efficient.
  • Scalability: The decoupled nature of Clean Architecture allows for scaling individual components as needed without affecting the entire application.
  • Maintainability: A well-structured and modular codebase is easier to understand, making it simpler to maintain and troubleshoot.

ASP.NET Core features supporting Clean Architecture

  • Dependency Injection: ASP.NET Core has built-in support for dependency injection, which enables loose coupling between components and simplifies testing.
  • Middleware: Middleware allows you to add and remove components in the request-response pipeline, providing flexibility in composing the application’s behavior.
  • Configuration: The configuration system in ASP.NET Core is highly extensible, allowing you to manage different environments and settings with ease.

Components of Clean Architecture

Clean Architecture is typically organized into four layers:

Domain Layer

The Domain Layer contains the core business logic and entities of the application. These entities represent the main concepts of the application and are independent of any specific technology or infrastructure.

Application Layer

The Application Layer is responsible for orchestrating the business logic and serves as a bridge between the Domain Layer and the other layers. It contains application-specific logic, such as validation and authorization, and communicates with the Domain Layer through interfaces.

Infrastructure Layer

The Infrastructure Layer contains the implementations of the interfaces defined in the Domain Layer. It is responsible for managing external dependencies, such as databases, APIs, and file systems.

Presentation Layer

The Presentation Layer is responsible for displaying data to the user and handling user input. In ASP.NET Core applications, the Presentation Layer typically consists of controllers, views, and view models.

Implementing Clean Architecture in ASP.NET Core

Now that we understand the core concepts of Clean Architecture, let’s go through the process of implementing it in an ASP.NET Core application.

Setting up the project structure

First, create a new ASP.NET Core project and organize it into the following folders:

  • Domain: Contains the domain entities and interfaces.
  • Application: Houses the application services, DTOs, and interfaces.
  • Infrastructure: Contains the implementations of the interfaces defined in the Domain layer.
  • Presentation: Consists of the controllers, views, and view models.

Configuring Dependency Injection

ASP.NET Core’s built-in dependency injection system is a powerful tool for managing dependencies between layers. Register your services and repositories in the Startup.cs file by using the AddScoped, AddTransient, or AddSingleton methods, depending on their desired lifetime.

Implementing Domain Entities and Interfaces

In the Domain folder, create the core business entities and define the interfaces for the services and repositories. These interfaces will later be implemented in the Infrastructure layer.

Creating Application Services and DTOs

In the Application folder, implement the application services that interact with the Domain layer through the interfaces. Use Data Transfer Objects (DTOs) to communicate between the Presentation and Application layers, ensuring a clean separation of concerns.

Building the Infrastructure and Presentation Layers

Finally, implement the Domain layer interfaces in the Infrastructure folder, and create the controllers and views in the Presentation folder.

Best Practices for Clean Architecture in ASP.NET Core

To ensure a robust implementation of Clean Architecture in your ASP.NET Core application, follow these best practices:

  • Keep the Domain layer free of any technology-specific dependencies.
  • Use the Dependency Inversion Principle to ensure loose coupling between layers.
  • Avoid circular dependencies between layers by implementing the interfaces in the correct layer.
  • Separate the concerns of your application by maintaining clear boundaries between layers.
  • Write unit tests for each layer, focusing on testing the business logic in the Domain layer and the application logic in the Application layer.


Clean Architecture is an effective way to build maintainable, testable, and scalable applications in ASP.NET Core. By following the principles and best practices outlined in this article, you can create a robust application that is easier to manage and extend. Implementing Clean Architecture in your projects will result in higher quality software and a more enjoyable development experience.


  1. What is Clean Architecture?
    • Clean Architecture is a software design paradigm that focuses on the separation of concerns and maintainability of code. It enforces modularity, testability, and scalability in software applications.
  2. Why should I use Clean Architecture in ASP.NET Core?
    • Clean Architecture complements the flexibility of ASP.NET Core and offers benefits like modularity, testability, scalability, and maintainability.
  3. What are the main components of Clean Architecture?
    • Clean Architecture typically consists of four layers: Domain, Application, Infrastructure, and Presentation.
  4. How can I implement Clean Architecture in an ASP.NET Core project?
    • To implement Clean Architecture in ASP.NET Core, you need to organize your project into layers, configure dependency injection, implement domain entities and interfaces, create application services and DTOs, and build the infrastructure and presentation layers.
  5. What are some best practices for implementing Clean Architecture in ASP.NET Core?
    • Some best practices include keeping the Domain layer free of technology-specific dependencies, following the Dependency Inversion Principle, avoiding circular dependencies, maintaining clear boundaries between layers, and writing unit tests for each layer.

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