How is Node.js different from traditional server-side technologies like Java or Python?
The key difference is the concurrency model.
Concurrency model — Node is single-threaded and non-blocking, handling thousands of concurrent connections on one thread via the event loop. Java and Python traditionally use a thread-per-request model, where each connection consumes a thread — expensive at scale.
Workload fit — Node excels at I/O-heavy workloads (APIs, real-time apps, streaming). Java is better for CPU-heavy enterprise systems, and Python shines in scripting, ML, and data work.
Avoid being biased toward Node.js. Interviewers appreciate when you can objectively compare technologies and explain when each is the better choice.
Focus on the concurrency model difference as the key technical distinction.