When would you use WebSockets instead of REST in a MERN app?
PICTURE THIS: STACK VS QUEUE
Simple meaning
Use WebSockets when the client must receive updates immediately without polling.
WHY — WebSockets instead of guessing?
Why interviewers care about WebSockets:
on WebSockets.
the situation, the default choice, and one exception - that reads as experience.
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:
- 1Use WebSockets when the
client must receive updates immediately without polling.
- 2REST is simpler for
CRUD and still stores the durable records.
- 3Many apps load history
over REST and stream live events over sockets.
- 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
Use WebSockets when the client must receive updates immediately without polling. REST is simpler for CRUD and still stores the durable records.