What are the pros and cons of Node.js?

0-2 years experience

1. 1How would you decide whether to use Node.js for a simple REST API that returns JSON data?
2. 2What happens if you write a CPU‑intensive loop in a Node.js request handler?
3. 3If you need to read a file and then send its contents over HTTP, how would you take advantage of Node's strengths?

2-5 years experience

1. 1We have a microservice written in Node.js that started experiencing high latency under load. Walk me through how you'd investigate whether the event loop is the bottleneck.
2. 2When integrating a third‑party library that uses native bindings, what trade‑offs do you consider about staying in the Node ecosystem?
3. 3Explain why a recent deployment caused memory leaks in a Node.js service and how you would fix it.

5-8 years experience

1. 1Design a high‑throughput real‑time chat system using Node.js. What architectural decisions would you make to mitigate the single‑threaded limitation?
2. 2If you need to run CPU‑heavy image processing alongside a Node.js web server, how would you structure the system to preserve responsiveness?
3. 3Discuss the pros and cons of using Node.js versus a compiled language for a latency‑sensitive trading platform.

8+ years experience

1. 1Your company is planning to migrate a legacy monolith written in Java to a microservice architecture, and you’re evaluating Node.js for many services. What long‑term maintenance and cross‑team considerations would influence that decision?
2. 2When standardizing a shared library across multiple teams, how would you address the risk of divergent Node.js versions and ecosystem churn?
3. 3If you need to guarantee backward compatibility for an internal API over several years, how does Node's rapid release cycle affect your strategy?