Nodejs8 min readUpdated Jun 17, 2026Technical Concept

Top 10 nodejs Questions in 2026

Top 10 nodejs Questions in 2026 focuses on why is node.js good for i/o-heavy services?. Node.js uses an event-driven nonblocking model that handles many concurrent I/O operations with relatively low overhead.

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Quick definition

Top 10 nodejs Questions in 2026 focuses on why is node.js good for i/o-heavy services?. Node.js uses an event-driven nonblocking model that handles many concurrent I/O operations with relatively low overhead.

Quick Summary

TopicQuestionsSourceCompany Claims
Nodejs10MongoDB qbankOnly shown when present in qbank

Scenario Questions

  • A dashboard freezes while processing a large response on the browser main thread. I would split CPU-heavy work, keep promise chains predictable, and verify improvement with interaction latency and long-task measurements.
  • A Node.js change causes slower responses after traffic increases. I would isolate the hot path, apply the smallest reversible fix, and verify the result with latency, error rate, and rollback readiness.
  • A Node.js change causes slower responses after traffic increases. I would isolate the hot path, apply the smallest reversible fix, and verify the result with latency, error rate, and rollback readiness.
  • A Node.js change causes slower responses after traffic increases. I would isolate the hot path, apply the smallest reversible fix, and verify the result with latency, error rate, and rollback readiness.

Common Mistakes

  • event-loop is good because it is faster. I would compare the workload, failure mode, and maintenance cost before using event-loop, then verify the result with production metrics.
  • streams is good because it is faster. I would compare the workload, failure mode, and maintenance cost before using streams, then verify the result with production metrics.
  • express is good because it is faster. I would compare the workload, failure mode, and maintenance cost before using express, then verify the result with production metrics.
  • worker-threads is good because it is faster. I would compare the workload, failure mode, and maintenance cost before using worker-threads, then verify the result with production metrics.
  • security is good because it is faster. I would compare the workload, failure mode, and maintenance cost before using security, then verify the result with production metrics.

FAQ

Practice

Practice these questions in a RivoHire mock interview.

Quiz

What runs first after the synchronous call stack becomes empty?

A. Macrotask queue
B. Microtask queue
C. setTimeout queue always
D. Browser rendering always

Correct answer: microtasks run after the stack clears and before the next macrotask.

Compact Interview Questions

Why is Node.js good for I/O-heavy services?

Node.js uses an event-driven nonblocking model that handles many concurrent I/O operations with relatively low overhead.

How do streams help in Node.js?

Streams process data in chunks, reducing memory usage and improving throughput for large payloads.

How should errors be handled in Express middleware?

Pass errors to error-handling middleware and return consistent responses without leaking internal details.

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