Why is Node.js popular?
JavaScript everywhere — same language on frontend and backend, easier hiring and code sharing.
High performance for I/O — non-blocking event loop handles thousands of concurrent connections efficiently.
Huge ecosystem — npm is the largest package registry, so most problems already have a library.
Fast development — lightweight, easy to prototype, minimal boilerplate.
Scalable by design — perfect for APIs, microservices, real-time apps, and streaming.
Strong corporate backing — used in production by Netflix, PayPal, LinkedIn, Uber, and others.
A strong answer connects popularity to architecture, developer productivity, ecosystem maturity, and the kinds of workloads Node.js handles well. Avoid repeating marketing phrases like 'it is fast' without explaining why.