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React Interview Questions

A short interview-prep course with Cassidy Williams: about 40 minutes on the React questions that come up most in interviews, from the virtual DOM to hooks.

Quick answer​

React Interview Questions is Scrimba's Pro, intermediate course, around 41 minutes taught by Cassidy Williams, a well-known engineer. It walks through common React interview questions: the virtual DOM, hooks, state, and the conceptual answers interviewers look for. It is a focused refresher, not a way to learn React. It suits someone who already knows React and has an interview coming up and wants to sharpen how they explain the concepts out loud.

Is it worth your time?​

Knowing React and explaining React under interview pressure are different skills. This short course targets the second one. In about 40 minutes Cassidy Williams runs through the questions that come up repeatedly (how the virtual DOM works, what hooks actually do, how state and re-renders behave) and models clear, concise answers. For the night before an interview, that is a high-value 40 minutes.

The honest caveat is scope. It is short and conceptual, not a coding bootcamp. It will not teach you React, and it will not replace hands-on practice if you freeze on live-coding rounds. Pair it with React Challenges for the build-it-fast side of interviews. On its own it covers the talk-about-it side well.

What you'll learn​

There is no module breakdown for this short course. Over roughly 40 minutes it covers the React concepts interviewers ask about most: what the virtual DOM is and why it matters, how hooks work and why React moved to them, how state and re-rendering behave, and the kind of trade-off reasoning interviewers want to hear rather than rote definitions. The real lesson is articulation: turning knowledge you already have into clean, confident answers.

Who it's for, and who should skip it​

It fits developers who already know React and have an interview coming up, and anyone who can write React but stumbles when asked to explain it in words.

Skip it if you are still learning React (do Learn React first), or if your interviews are heavily live-coding-based, in which case practice-focused work like React Challenges matters more than concept review.

Prerequisites​

Working React knowledge: components, props, state, hooks, and a general sense of how React renders. The course refreshes and frames these for interviews rather than teaching them.

Where it fits​

This is an interview-prep slot in the Frontend Developer Path and the Fullstack Developer Path, best used near the end, once you know React and are preparing to apply for roles.

Free or Pro​

This is a Pro course, so it needs a Scrimba subscription. Pro also unlocks the full career paths, the coding challenges, the private Discord, and path certificates. See current plans for what Pro costs in your region.

Strengths and limits​

What it does well: it is short and high-yield for interview prep, it is taught by a recognized engineer with real hiring-side perspective, and it models how to answer rather than just listing facts.

Where it is limited: it is brief and conceptual, it will not teach React, and it does not cover the live-coding side of interviews, which needs separate practice.

View React Interview Questions on Scrimba (opens in a new tab)

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