I'm not sure if TFA implies this (it uses too much of his personal jargon for me to understand everything, and it's Friday) but consider this solution based on his transaction log section: you should use the same database that persists the idempotency key to persist the message, and then consume the messages from the CDC/outbox-style. Meaning, the database simply acts as an intermediate machine that dedupes the flow of messages. Assuming you're allowed to make the producer wait.