.NET API | Clean Architecture

What is Clean Architecture? Clean Architecture is a software design pattern that promotes separation of concerns and dependency inversion. It emphasizes the separation of the application’s core business logic from external dependencies, such as databases, frameworks, or APIs, to make the codebase more maintainable and testable. The core business logic is at the center of the architecture, and the surrounding layers depend on it, following the dependency inversion principle.

The Layers of Clean Architecture Clean Architecture typically consists of four main layers:

1. Domain Layer: This layer represents the core business logic of the application. It contains domain entities, value objects, and business rules. This layer is independent of any external dependencies and does not have any references to other layers.
2. Application Layer: This layer contains use cases or application services that orchestrate the interactions between the domain layer and the infrastructure layer. It implements the business rules and logic using the domain entities and value objects from the domain layer.
3. Infrastructure Layer: This layer contains the implementations of external dependencies such as databases, APIs, frameworks, or any other infrastructure-related components. It provides the necessary infrastructure for the application layer to interact with the external world.
4. Presentation Layer: This layer is responsible for handling the user interface and user interactions. It can be a web API, a web application, a desktop application, or any other user-facing interface.

Practical Example: Building a .NET API with Clean Architecture Let’s consider an example of building a .NET API for a simple online shopping application using Clean Architecture. The application allows users to browse and purchase products from various vendors. Here’s how we can implement Clean Architecture in this scenario:

Domain Layer:

In the domain layer, we define the core business logic of the application, such as domain entities, value objects, and business rules. For example, we can define domain entities like Product, Vendor, and Order, along with their properties and behaviors. We can also define value objects like Price, Quantity, and Address, and implement business rules like validation, calculations, and constraints.

public class Product
{
    public int Id { get; set; }…