How do you scale a Node API horizontally?
PICTURE THIS: STACK VS QUEUE
Simple meaning
Run multiple processes or containers behind a load balancer and keep the API stateless.
WHY — Deployment instead of guessing?
Why interviewers care about Deployment:
question about Deployment.
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:
- 1Run multiple processes or
containers behind a load balancer and keep the API stateless.
- 2Sessions, rate limits, and
Socket.IO must use Redis or another shared store.
- 3Sticky sessions are a
last resort because they fight even load distribution.
- 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
Run multiple processes or containers behind a load balancer and keep the API stateless. Sessions, rate limits, and Socket.IO must use Redis or another shared store.