What you're probably looking for is continuations, combine them with serialisation and you can have stateless (in that the state is in a persistent store and ca

What you're probably looking for is continuations, combine them with serialisation and you can have stateless (in that the state is in a persistent store and can be picked up by any application server) workflow processing. You stumbled upon a drawback yourself though: >And as long as the back-end servers were all running the same version of my code the continuation could be serialised and then picked up later with business logic that has since changed in your application, whether through changing requirements or bugfixes. Therefore personally, (I'm not saying there aren't successful business implementations of continuations, just my own observations), in the wild, I've mostly seen long running async workflows being put together by either state machine modelling in whatever language the programmers are using to let workers run through multi-stage processes, or use of workflow engines to hoist the orchestration to a tooling layer and the regular "programming" is in the building blocks.