Optimistic UI

The interface commits to the outcome it expects. The heart fills, the count goes up, the message appears in the thread, and the request goes out behind it. For actions that almost always succeed, this is the difference between an app that feels instant and one that feels like a form.

The pattern is only half done at that point. The other half is reconciliation: what happens on the roughly one attempt in a hundred that fails. The state has to go back, and the user has to be told, in a way that does not read as a bug they caused. Rolling back silently is worse than never having been optimistic.

Use it where the action is small, likely to succeed, and cheap to undo. Do not use it where being wrong is expensive: payments, deletions, anything the user would act on before the truth arrives. When the wait is unavoidable, show the wait honestly with a skeleton screen instead.