idempotency

Trace a dropped stream through bounded queues, engine cancellation and safe resource release; define what retries and incomplete delivery mean.

Trace usage from execution to one settled charge. Distinguish requests, attempts and events, then handle cancellation, late records, replay and reconciliation.

Connect POST-and-poll semantics to durable item results, retry ownership and deadline capacity. Explain how cheap batch execution can still miss the delivery contract.

Implement bounded retries with full jitter, a shared credit budget and a cooperative deadline. Test repeatability and explain what a timeout leaves uncertain.

Design job creation, cancellation and listing around retries, durable ownership and an explicit pagination contract.