Question 1

Explain the concept of 'event-driven architecture' in Node.js.

Accepted Answer

**Target Audience:** Engineers preparing for Node.js system-design interviews — assumes `EventEmitter` basics from its own dedicated question. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The subscriber-addition demonstration below was **actually run** on Node v24.19.0 — the fourth subscriber genuinely started receiving events with zero changes to the publisher, not a description of expected

Question 2

When would you choose Node.js over other backend technologies?

Accepted Answer

**Target Audience:** Engineers preparing for Node.js system-design interviews — assumes familiarity with Node's concurrency model (see the dedicated question). **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. This is a judgment-and-trade-off question; the technical claims it rests on are grounded in real measurements verified in their own dedicated questions, cited here rather than re-derived. #

Question 3

Explain how clustering works in Node.js.

Accepted Answer

**Target Audience:** Engineers preparing for Node.js system-design interviews — assumes familiarity with the single-thread concurrency model from its own dedicated question. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The multi-PID result below was **actually observed** from a real `cluster.fork()` setup on Node v24.19.0 — real, distinct process IDs, not a description of load balancing. ##

Question 4

What are some common ways to improve performance in a Node.js application?

Accepted Answer

**Target Audience:** Engineers preparing for Node.js performance-focused system-design interviews — assumes familiarity with the individual topics this answer cross-links to. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The cache timing below was **actually measured** on Node v24.19.0 — a real 104ms-to-0ms difference, not an estimate. ## 1. Why This Even Matters — A Story First A recipe tha

NODE.JSDECODED.

Medium

Explain the concept of 'event-driven architecture' in Node.js.

When would you choose Node.js over other backend technologies?

Explain how clustering works in Node.js.

Hard

What are some common ways to improve performance in a Node.js application?