Interview kitsBlog

Your dream job? Lets Git IT.
Interactive technical interview preparation platform designed for modern developers.

XGitHub

Platform

  • Categories

Resources

  • Blog
  • About the app
  • FAQ
  • Feedback

Legal

  • Privacy Policy
  • Terms of Service

© 2026 LetsGit.IT. All rights reserved.

LetsGit.IT/Categories/Next.js
Next.jseasy

What is code splitting and how does `dynamic()` help in Next.js?

Tags
#code-splitting#dynamic-import#performance
Back to categoryPractice quiz

Answer

Code splitting loads code only when needed instead of shipping one big bundle. `next/dynamic` lets you lazy-load heavy components (and optionally disable SSR for them), improving initial load performance.

Advanced answer

Deep dive

Expanding on the short answer — what usually matters in practice:

  • Context (tags): code-splitting, dynamic-import, performance
  • Lifecycle: what happens at runtime (render/build, request/response, background jobs).
  • Caching: where cache lives, cache keys, how to invalidate without chaos.
  • Security: authn/authz, secrets, attack surface (SSRF/CSRF).
  • Explain the "why", not just the "what" (intuition + consequences).
  • Trade-offs: what you gain/lose (time, memory, complexity, risk).
  • Edge cases: empty inputs, large inputs, invalid inputs, concurrency.

Examples

A tiny example (an explanation template):

// Example: discuss trade-offs for "what-is-code-splitting-and-how-does-`dynamic()`-"
function explain() {
  // Start from the core idea:
  // Code splitting loads code only when needed instead of shipping one big bundle. `next/dynam
}

Common pitfalls

  • Too generic: no concrete trade-offs or examples.
  • Mixing average-case and worst-case (e.g., complexity).
  • Ignoring constraints: memory, concurrency, network/disk costs.

Interview follow-ups

  • When would you choose an alternative and why?
  • What production issues show up and how do you diagnose them?
  • How would you test edge cases?

Related questions

Next.js
`next/link` prefetching: what does it do and how can you control it?
#nextjs#link#prefetch
Next.js
Browser-only library in App Router: how do you use it without breaking SSR/Server Components?
#nextjs#server-components#client-components
Next.js
What does `next/font` solve and how does it reduce layout shift (CLS)?
#nextjs#fonts#performance
Next.js
What does `next/image` do for you (and why use it)?
#nextjs#images#performance
Next.js
Edge runtime vs Node.js runtime in Next.js — when choose which?
#edge#runtime#nodejs
Next.js
Name two practical ways to improve Next.js performance.
#performance#bundling#next-image