19 / PERCEIVED PERFORMANCE
Optimistic Rollback
The problem
Optimistic updates feel instant, but when the server rejects the change the UI must correct itself without confusing the user.
The solution
The UI updates instantly and rolls back with a note if the server rejects it.
Experiment
Task: Toggle the switch and watch failures roll back.
NAIVE
Notifications off
statusidle
modeawait
THOUGHTFUL
Notifications off
statusidle
modeoptimistic
Play with the values
1200ms
0.4
How it works
Seen in
Settings toggles
Preferences flip instantly and revert with a message if saving fails.
Reactions
Likes appear immediately but roll back cleanly on a network error.
Inline edits
Edited fields show at once and restore prior values if rejected.
Cart updates
Quantity changes reflect immediately, correcting if the server disagrees.