FIELD 02 / FAILURE REPORT
One webhook created two actions
A timeout led the sender to retry while the first action had already completed.
Situation
The workflow treated each delivery as new work and acknowledged only after the downstream action returned.
Finding
The second delivery repeated an external side effect because no stable operation key or completed state existed.
Response
- Persist operation key first
- Acknowledge accepted work
- Make action idempotent
- Add reconciliation view
ARCHITECTURE LESSONAt-least-once delivery requires exactly-once business behavior to be designed, not assumed.