Handle events out of order.
A delivery update arrives before a pickup update. Reproduce the sequence and test the state machine.
Event fixtures, transition tests, and an explanation of the fix.
Use this starter prompt
Reproduce [shipment state issue] in [repository] with synthetic carrier events. Test duplicates, delayed messages, missing events, and time-zone boundaries. Implement the agreed transition rules and run regression tests. Do not send requests to live carriers or deploy.



