How does the Node.js event loop work?

Question

Accepted Answer

**TL;DR.** Practically: Node runs your synchronous code first, then enters the **event loop**, which in each tick runs a phase's callbacks and, after *every* callback, drains **microtasks** (process.nextTick → Promises) before moving on. The single thread keeps cycling phases until no timers, I/O, or immediates remain, then exits.

Node.js Interview Library

Question Catalog

How does the Node.js event loop work?

Difficulty Distribution

Hiring Companies

Tested Topics

Study Guide