How do you implement custom middleware in Django?

Custom middleware in Django is a way to process requests globally before they reach the view or after the view has processed them. To create custom middleware:

1. Create a new Python file for your middleware.
2. Define a class with __init__ and __call__ methods or specific middleware methods like process_request.
3. Add your middleware class to the MIDDLEWARE setting in settings.py.

Example:

class SimpleMiddleware:
    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        # Code to execute for each request before the view
        response = self.get_response(request)
        return response

This middleware can be used for logging or modifying requests/responses.