The article speaks of two usecases, work queue and pub/sub event log. You talk about the first and the comment you reply to the latter. You need event sequence

The article speaks of two usecases, work queue and pub/sub event log. You talk about the first and the comment you reply to the latter. You need event sequence numbering for the pub/sub event log. In a sense this is what Kafka IS architecturally: The component that assigns event sequence numbers.