Optimistic UI
The interface updates immediately on user action — assuming success — before the server response.
What you're seeing
Click "like" and the count goes up instantly. Add an item and it appears immediately.
Where you'll see it
Social interactions, list additions, form fields.
Difficulty
Medium — 3/5
Libraries that build it
ReactSWRcustom JS
Ready to prompt — paste this into your AI coding tool
"Update UI state immediately on action, make async call in background, rollback with animation on error"