What are action filters?
PICTURE THIS: HOW TO EXPLAIN IT
Simple meaning
Filters run before or after actions for cross-cutting concerns like auth, logging, and caching.
WHY — Filters instead of guessing?
Why interviewers care about Filters:
who only read docs from people who shipped.
and tied to .NET MVC work.
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:
- 1Filters run before or
after actions for cross-cutting concerns like auth, logging, and caching.
- 2Why it exists
They keep controllers thin.
- 3Authorization filters run early
in the pipeline.
- 4Give an example
One tiny concrete case you can say aloud.
- 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
Filters run before or after actions for cross-cutting concerns like auth, logging, and caching. They keep controllers thin.