Next.js shows up in more frontend and full-stack job postings every year, and the framework keeps moving fast enough that last year's interview prep is already out of date.
PPR is the stable default in Next.js 16. "use cache" replaced the confusing implicit fetch caching from Next.js 13/14. params and searchParams are now Promises. middleware.ts is now proxy.ts. Turbopack is the default bundler for both next dev and next build.
If your prep material does not cover these, you're walking in with an outdated mental model.
This guide covers 30 questions across five categories:
-
Fundamentals: what Next.js adds over plain React, rendering strategies, file-based routing,
next/image -
App Router conventions:
layout.tsx,loading.tsx, route groups, parallel routes, middleware -
Server vs. Client Components: when to use
"use client", hydration errors, Suspense and streaming, Server Actions -
Data fetching and caching:
"use cache",revalidatePathvs.revalidateTag, ISR, the four cache layers, async Request APIs -
Performance and advanced: Partial Prerendering (PPR), Turbopack,
next/imageprops and Core Web Vitals, authentication
Each answer is written the way you'd say it out loud in an interview, not the way the docs phrase it, with code samples for the questions where you might be asked to write something live.
There's also a quick reference table at the end with all 30 questions and their core concepts, useful for a final scan the night before.
Read the full guide with all answers and code samples:
Top comments (0)