MediatR
MediatR is a .NET library that implements the Mediator pattern, providing in-process messaging for decoupling request/response and notification handling in applications. It simplifies communication between objects by routing requests through a single mediator object, promoting loose coupling and separation of concerns. It is commonly used in C# applications, especially with ASP.NET Core, to implement clean architecture patterns like CQRS (Command Query Responsibility Segregation).
Developers should learn MediatR when building maintainable, scalable .NET applications that require decoupled components, such as in microservices or complex domain-driven designs. It is particularly useful for implementing CQRS, where commands and queries are handled separately, reducing dependencies and improving testability. Use cases include handling business logic in a clean way, managing cross-cutting concerns like logging or validation, and organizing code in line with SOLID principles.