Optimistic updates with useOptimistic

Trading certainty for responsiveness

An optimistic update renders the outcome the moment the user acts, then reconciles with whatever the server actually returns. For a like button or a todo checkbox, that removes a round trip from the interaction entirely.

The hook keeps the optimistic value only until the action settles, so a failure reverts to the real state without any rollback code of your own. What you do owe the user is a message — silently reverting a change looks like a bug.

Reserve the technique for actions that almost always succeed and are cheap to undo. Optimistically showing a completed payment is not responsiveness, it is lying.