> The goal of the outbox pattern is at-least-once publishing though, not only-once.
Right, which is why it's an unacceptable solution to 'transacting over postgres and Kafka', and why I wouldn't want to work for a company that wants me to believe differently.
I think you're just using "transaction" in a different sense than what the interviewer meant; "guarantee that an event happened in addition to a database update" sounds like at-least-once to me, and it's normally what you would want in this kind of system.
Right, which is why it's an unacceptable solution to 'transacting over postgres and Kafka', and why I wouldn't want to work for a company that wants me to believe differently.
And there's a better solution anyway: just K.