What is Repository Pattern in C#?

The Repository Pattern is a software design pattern used to separate an application's business logic from data-access logic. Instead of allowing business services to directly interact with Entity Framework Core or a database, the repository provides an abstraction through which the application can perform operations such as retrieving, creating, updating, and deleting data. For example, an application might define an IProductRepository interface with methods such as GetByIdAsync(), GetAllAsync(), AddAsync(), and DeleteAsync(). An implementation can then use Entity Framework Core to execute the actual database operations. The main benefits include: Separation of concerns Easier unit testing Centralized data-access logic Reduced coupling between business and database layers Easier replacement or modification of the underlying data-access technology However, developers should not automatically introduce a repository on top of Entity Framework Core. DbContext and DbSet already provide many repository and unit-of-work capabilities. In simple applications, adding another abstraction can create unnecessary complexity. Expert perspective: Use the Repository Pattern when it provides a genuine architectural benefit, particularly when the application needs a clear domain/data-access boundary or multiple data sources—not simply because it is a commonly taught pattern.