State Management · Middle · Question 73 of 75

What is the difference between optimistic and pessimistic updates?

✓Correct answer: Optimistic updates change the UI before the server confirms and roll back on error; pessimistic updates wait for the response
2Optimistic updates never contact the server
3Pessimistic updates are always faster

Explanation

Optimistic UI feels instant for likely-successful actions (likes, toggles). Use pessimistic updates for payments and anything hard to undo.

Further reading

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