Not the parent, but here's one that I hit recently: I hoisted the state of an input box up a few layers because other parts of my app are affected by the curre

Not the parent, but here's one that I hit recently: I hoisted the state of an input box up a few layers because other parts of my app are affected by the current typed content. Since I'd been careless passing closures in as props to expensive components, they were getting re-rendered on every keystroke. It was noticeably sluggish.