> 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.
