Wow. Thanks for the extra explanation about when the different approach can benefit.

I love you. Will definitely give bus-workflow a thorough shot.

And a very last question if you could spare a bit more time..

Again the user signup & event flow,

When Workflow calls EmailService.sendEmail (given that the communication is via RPC and EmailService.sendEmail is an async operation that will resolve if the email was sent successfully), should Workflow wait for the sendEmail operation to resolve and complete the flow? Or should EmailService dispatches an event EmailSent so that Workflow can complete the flow?

This is a bit off the topic but I've been sticking with RPC style call rather than Events but still don't know yet what the best practice is.

Many Thanks