It is worth noting that the jetstream API (to me) (not that experienced) to lack some of the features of Kafka w.r.t. replayability - for instance I can’t easily say “go back and re-run messages from X point-in-time”. Instead it may be necessary to write custom handlers for replay or safeguard your systems to be very idempotent (a good pattern in event driven systems, but not one that is explicitly required by Kafkaesque messaging systems).