1. The access collection black hole You need Figma access, Google Analytics, WordPress admin, GitHub, and the client's Slack. You ask. They forward a password email from two years ago. You ask again. Their developer says they'll get back to you. Three days pass. The fix: Send a single, complete access list on Day 1 — not "we'll need some access" but the exact list, with specifics for each tool,
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