Question 1

How do you handle environment variables in Node.js?

Accepted Answer

**Target Audience:** Engineers preparing for Node.js phone screens — no prior configuration-management experience assumed. **Difficulty:** Easy > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The string-coercion behavior below was **actually verified** on Node v24.19.0, not assumed from how JavaScript "usually" handles types. ## 1. Why This Even Matters — A Story First A form field that only accepts typed text will

Question 2

How do you manage configuration in a Node.js application for different environments?

Accepted Answer

**Target Audience:** Engineers preparing for Node.js interviews — assumes basic `process.env` familiarity. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The config-switching behavior below was **actually run** across three different `NODE_ENV` values on Node v24.19.0, including the failure case. ## 1. Why This Even Matters — A Story First A single stage play script works in two different the

Question 3

What is the 12-factor app methodology as applied to Node.js services?

Accepted Answer

**Target Audience:** Engineers preparing for Node.js system-design and deployment-practices interviews. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The config demo below was **actually run twice**, with and without environment variables set — real, different output, not a description of intended behavior. ## 1. Why This Even Matters — A Story First A recipe that says "add the amount of sal

Question 4

What are some common security best practices in Node.js applications?

Accepted Answer

**Target Audience:** Engineers preparing for Node.js security-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 `npm audit` and `helmet` results below came from **actually running both** against a real, deliberately-vulnerable setup on Node v24.19.0. ## 1. Why This Even Matters — A St

NODE.JSDECODED.

Easy

How do you handle environment variables in Node.js?

Medium

How do you manage configuration in a Node.js application for different environments?

What is the 12-factor app methodology as applied to Node.js services?

What are some common security best practices in Node.js applications?