What is the role of middleware in the Django architecture and why is it necessary?

Middleware in Django are components that process requests and responses at intermediate stages between the server and views. They allow for the integration of additional logic such as authentication, sessions, caching, error handling, and other aspects without modifying the view code itself.

Middleware is necessary for:

• Centralized processing of requests and responses
• Reusing code that affects all or many requests
• Separation of concerns and simplifying architecture

Each middleware is a class with methods that are called when a request is received and a response is sent. They can modify the request, interrupt processing, or modify the response.

Example: middleware for logging request processing time.