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
Part 2 of 5 in The New Engineering Contract - what it means to lead engineers when AI is doing more of the coding. Stripe never skipped the boring stuff. They ship 1,300 AI PRs a week. Amazon skipped it. Their storefront went down for six hours. Kent Beck wrote the answer in Extreme Programming Explained in 1999. We read it. Then chose velocity anyway. A friend of mine leads engineering at a funde