What happens in the browser between a change to the DOM or styles and pixels appearing on screen? How do you use that to keep animations and scrolling from janking?
~4 min by voice
How to approach it
This checks whether the candidate understands the browser rendering pipeline, meaning which changes trigger which stages. And whether they can apply it in practice: choose properties that are cheap to animate, avoid layout thrashing, work with layers sensibly, and diagnose problems in DevTools.
The interviewer will ask this question and listen. Think out loud and ask for a hint if you need one. When you're done, pause or tap “That's my answer”. In about a minute, your score and the points you covered show up here.