Memory leaks in JavaScript don't announce themselves with an error. They show up as a heap that grows by 20MB per minute — invisible in a five-minute Lighthouse run, fatal in a six-hour production session. Why React apps leak: A useEffect that opens a WebSocket and never closes it on unmount. A setInterval without clearInterval in the cleanup return. A global Map that grows without bound. In each
Random 30–50ms freezes with no obvious long tasks in the Performance panel often have one root cause: the garbage collector. V8 pauses JavaScript execution to reclaim memory, and if your allocation rate is high enough, those pauses happen frequently — creating jank that shows up as a sawtooth pattern in the memory timeline rather than a spike in the flame chart. What this covers: How V8's generati
Ages ago when CSS grids came with a repeat() function to simplify defining repetitive columns and rows, I was not alone in wishing for this function to be made generic and work in any context. After seeing Wes Bos on BlueSky wishing for this exact concept, specifically for repeating segments in a shape() definition, I chimed in with my +1's on making repeat() generic across CSS Without delay, @no