Questions
11 of 15
1Explain the event loop.
2How does the browser's event loop differ from Node.js's event loop?
3What is the difference between the microtask queue and the macrotask (callback) queue?
4How would you profile and detect event loop lag in a production Node.js service? What tools and metrics do you use? (e.g., perf_hooks, Clinic.js, event_loop_utilization)
5How do you design a CPU-intensive task (e.g., image processing, ML inference) in a Node.js app without blocking the event loop?
6How does the event loop relate to memory leaks? Can retained closures in the callback queue prevent garbage collection?
7What is 'starvation' in the context of the event loop? Give a real-world example.
8How does the event loop handle long-running synchronous code? What is 'blocking the event loop' and how do you avoid it in production?
9How does Promise.then() differ from setTimeout() in terms of execution order?
10How do streams and backpressure in Node.js relate to the event loop? Why does improper stream handling block or overload the loop?
11What could be the disadvantages of process.nextTick()
12Explain process.next.tick()
13What is queueMicrotask()? How does it differ from Promise.resolve().then()?
14Why use process.nextTick()?
15What strategies do you use to keep the event loop healthy at scale? (offloading, chunking, job queues like BullMQ, worker threads)
