Backend & systems·Queues, streams and delivery semantics
you acknowledge the message first and then process it, so a crash mid-processing means it is simply gone.
At-most-once delivery
A guarantee that a message is never delivered twice, and may be delivered zero times. It is the cheapest option and the right one for high-volume telemetry where a lost sample does not matter. It is the wrong one for anything a user paid for or is waiting on.