Question 1

How do you run Node.js processes as a background service?

Accepted Answer

**Target Audience:** Engineers preparing for Node.js/DevOps phone screens — assumes very basic `child_process`/Unix process familiarity. **Difficulty:** Easy > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The detached-process survival below was **actually run** on this machine, with a real log file confirming the child kept working after its parent had already exited. ## 1. Why This Even Matters — A Story First A c

Question 2

How do you handle uncaught exceptions and unhandled promise rejections in Node.js?

Accepted Answer

**Target Audience:** Engineers preparing for Node.js interviews — assumes basic Promise/async familiarity. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. Both the handled and the genuinely unhandled (crashing) cases below were **actually executed** on Node v24.19.0 — a real exit code, not an assumption. ## 1. Why This Even Matters — A Story First A building has two entirely separate emergency

Question 3

What is PM2 and what does it add over running `node server.js` directly?

Accepted Answer

**Target Audience:** Engineers preparing for Node.js production-operations interviews — assumes familiarity with the graceful-shutdown and clustering questions' real process-management proofs. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The restart behavior below was **actually run** — a real crashing script, a real PM2 daemon, real distinct PIDs captured from real logs — not a description o

Question 4

What is the difference between operational and programmer errors in Node.js?

Accepted Answer

**Target Audience:** Engineers preparing for Node.js interviews — assumes basic try/catch and custom Error class familiarity. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The branching logic and the crash-on-bug pattern below were both **executed on Node v24.19.0** — the exact output, including a real process exit code, is pasted in. ## 1. Why This Even Matters — A Story First A pilot has t

Question 5

How do you handle graceful shutdown in a Node.js application?

Accepted Answer

**Target Audience:** Engineers preparing for Node.js system-design interviews — assumes familiarity with the PID-1/container signal-handling question's SIGTERM mechanics. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The `server.close()` behavior below was **actually executed** against a real HTTP server on Node v24.19.0 — including an honestly-reported, unexpectedly long delay, not a cleaned-

NODE.JSDECODED.

Easy

How do you run Node.js processes as a background service?

Medium

How do you handle uncaught exceptions and unhandled promise rejections in Node.js?

What is PM2 and what does it add over running `node server.js` directly?

What is the difference between operational and programmer errors in Node.js?

Hard

How do you handle graceful shutdown in a Node.js application?