It’s not just about scale though, it can be useful where you own both components. The producer just produces events, as long as the queue is available. no retry

It’s not just about scale though, it can be useful where you own both components. The producer just produces events, as long as the queue is available. no retry is needed if the other side is having a problem or being updated. The messages sit in the queue until the other components can consume them. Especially useful when producer and consumers are running at different rates and the queue becomes a buffer. There’s also a difference in making a command to another service vs event or state notification. In the case of a command you often want to wait and find out if it went ok. Events or states published onto a queue are more of a case of “here is a thing that happened, deal with it how you wish”