How do ETags and 304 responses reduce API load?
PICTURE THIS: A REST CALL
Simple meaning
The server hashes or versions a representation and sends it as ETag.
WHY — HTTP instead of guessing?
Why interviewers care about HTTP:
question about HTTP.
trade-offs, and what you would actually do on a Full Stack 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:
- 1The server hashes or
versions a representation and sends it as ETag.
- 2Why it exists
The client repeats If-None-Match
- 3if nothing changed, the
server returns 304 with no body.
- 4This helps somewhat cacheable
GETs but is weaker than a dedicated cache for hot keys.
- 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
The server hashes or versions a representation and sends it as ETag. The client repeats If-None-Match