#event

Handle duplicate, delayed and out-of-order webhook events safely with deduplication, replay rules and idempotent state transitions.

Design travel-booking state around create, confirm, modify, cancel, fail and reconcile events with explicit ordering and idempotency.

Model travel pricing as timestamped observations and change events instead of only overwriting mutable current-price state.

Design deterministic reconciliation across booking, payment, cancellation and supplier events with explicit authority and audit rules.