>> There would be no net difference to pass a result forward compared to back to the caller. > For example, A knows it has called B, so if there is no response

>> There would be no net difference to pass a result forward compared to back to the caller. > For example, A knows it has called B, so if there is no response it knows that it has to handle an error, do a rollback and whatnot. Good point. Many application designs wouldn't work as-is in the "pass forward" approach. I hesitate to say in response: "well, then you're architecting it wrong". But perhaps there is a grain of truth in that. Maybe it is hard tradeoff.