Comment by geomagilles

Indeed - but I do not think it's related to the question. The question here is: how do I - as a developer - implement a workflow? Still there are numerous BPM solutions, but often overly sophisticated. You have AWS SWF, but complicated to use, Airflow but in Python only, your own implementation using queues, database, etc... Look at the diversity of answers: there is no obvious answer right now.