Does the yCrash Node.js hook affect my application's performance?

The hook adds negligible overhead in normal operation. It stays idle until the yc-360 script actually requests a capture, and most of what it reports during a capture is data V8 and Node.js are already tracking internally, so reading it doesn't require expensive work on its own.

CPU Profile is the one exception worth calling out. It uses V8's own sampling profiler for the duration of its capture window, which carries a small overhead while it's running. That overhead only applies while a CPU Profile capture is in progress, not while the hook is otherwise idle.