What Node.js Does While JavaScript Awaits
The lesson runs a short async function and pauses at await. A timeline shows the current JavaScript stack returning, the operation progressing through runtime and platform facilities, and the continuation becoming runnable after the promise settles.
The demonstration then inserts a long synchronous loop to show why the event loop cannot run another JavaScript callback while that work occupies the thread. It distinguishes I/O waiting from worker-pool tasks and CPU-heavy JavaScript, noting that the exact path depends on the API and platform. Companion material: async execution article, resumption trace, and Node.js event-loop guidance.
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