Working on some React Native gigs recently, I noticed something off: slow search, weird lag, and my SSD creeping into red.

Turns out Xcode had quietly stashed 80+ GB of cruft I didn’t need. Simulator junk, build artifacts, random cache bloat - all piling up under ~/Library.

This wasn’t a “my Mac is slow” moment. To me: it was an engineering hygiene problem.

Here’s what I cleared:

~/Library/Caches
~/Library/Developer/Xcode/DerivedData
~/Library/Developer/Xcode/iOS DeviceSupport

Also peeked inside:

~/Library/Application Support
~/Library/Logs

• DerivedData is safe to nuke - it just holds past build outputs.
• iOS DeviceSupport is where every simulator and physical iOS version you’ve ever connected goes to rot.
• And Caches is the usual suspect.

Why this matters

• Faster Spotlight indexing
• Clean rebuilds when needed
• Avoid random Xcode weirdness in React Native projects
• Less SSD wear
• More headroom, less clutter

I treat this kind of cleanup the way I treat dead docker volumes or broken symlinks in infra: small resets that keep the system sharp.

If you’re running React Native or just juggling multiple iOS projects, it’s worth taking 10 minutes to do this. Your SSD - and future self - will thank you.