What is the difference between the old process_request hooks and modern __call__ middleware?
PICTURE THIS: RAG CHATBOT
Simple meaning
Legacy mixin-style middleware implemented process_request, process_view, process_exception, and process_response.
WHY — Middleware instead of guessing?
Why interviewers care about Middleware:
contrast on Middleware, not two memorised paragraphs.
the developer, then one case where picking wrong hurts.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1Legacy mixin-style middleware implemented
process_request, process_view, process_exception, and process_response.
- 2Modern middleware is a
callable class whose __init__ receives get_response and whose __call__ wraps the request.
- 3You can still implement
process_view as a method
- 4Give an example
Django's adapter supports both styles.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
Legacy mixin-style middleware implemented process_request, process_view, process_exception, and process_response. Modern middleware is a callable class whose __init__ receives get_response and whose __call__ wraps the request.