#JavaScript

Interaction to Next Paint replaced First Input Delay as a Core Web Vital. If your site felt fast in 2023 and 'got slow' since, INP is probably why — and the fix is mostly about your main thread.

Your production bundle is bigger than you think, and you probably can't name half of what's in it. Here's how to look inside and cut the weight that matters.

Scroll, resize, input, and mousemove fire faster than your code can keep up. Debounce and throttle are how you stop paying the event-loop tax — if you pick the right one.

Most React memoization is cargo-culted and does nothing. Here's how to tell which re-renders cost you and where useMemo, useCallback, and memo earn their keep.

After profiling 50 production React apps, the same five problems showed up again and again. None of them were exotic — and all of them were fixable.