How does HTTP caching and Cache-Control affect a SPA?
PICTURE THIS: A REST CALL
Simple meaning
Hashed asset filenames can be cached immutable for a year while index.html stays no-cache so users get new hashes.
WHY — Performance instead of guessing?
Why interviewers care about Performance:
question about Performance.
trade-offs, and what you would actually do on a Frontend project - not buzzwords.
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:
- 1Hashed asset filenames can
be cached immutable for a year while index.html stays no-cache so users get new hashes.
- 2APIs need their own
cache rules or the UI shows stale JSON.
- 3Service workers can override
this and are a common source of 'hard refresh fixes it' bugs.
- 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
Hashed asset filenames can be cached immutable for a year while index.html stays no-cache so users get new hashes. APIs need their own cache rules or the UI shows stale JSON.