In what cases is there a need to use middleware in a system architecture?

Middleware is used in system architecture in the following cases:

• Integration of heterogeneous systems — when it is necessary to ensure interaction between different applications, platforms, or services.
• Communication management — middleware can handle message exchange, routing, data transformation.
• Security assurance — authentication, authorization, and encryption are often implemented at the middleware level.
• Load balancing and scalability — distributing requests among servers.
• Caching and performance optimization — middleware can store frequently requested data.
• Simplifying development — providing standard APIs and services for applications.

For example, in C#, middleware is often used in ASP.NET Core for processing HTTP requests, where each middleware component can perform its task (logging, authentication, error handling) before passing the request further.