What are process.nextTick() and setImmediate()? How do they differ?

Short answer: process.nextTick() queues a callback to be invoked immediately after the current operation completes, before the event loop continues.

Explain a bit more

setImmediate() queues a callback to run on the next iteration of the event loop.

Example code

process.nextTick(() => console.log('nextTick')); setImmediate(() => console.log('setImmediate')); console.log('sync'); Output: sync nextTick setImmediate nextTick runs before any I/O or timers; setImmediate runs after I/O callbacks.

Real-world example (ShopNest)

A ShopNest BFF in Node.js aggregates catalog and price APIs for the React storefront.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.