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Aleksei Aleinikov
Aleksei Aleinikov

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How Node.js Event Loop Really Handles I/O in 2025

If Node.js is single-threaded, why doesn’t it freeze on I/O? The answer lies in the event loop’s phases — timers, poll, check, microtasks — and how callbacks move through them.

In this guide I break down the loop with real-world patterns to stop interval drift, avoid starvation, and keep servers responsive under heavy load.

https://levelup.gitconnected.com/how-node-js-squeezes-i-o-performance-in-2025-6c563951d214

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