Hi @Nele - I had attended your unconference session yesterday! 
So I was trying to model my use case where I need to assign the task to the user in my application, as well as to send a notification for the user. So what I understand is that I need to have a reference to the task ID so that the user can complete the task on my app.
When the execution reaches this step, I need to trigger an external task. For that I have assigned the variable as below,
I have modeled the sub process as below,
What is happening is that the variable gets set correctly, but the sub process is not executing. So I tried opening cockpit and changed this userTaskStart variable from true to false, and then again to true. When that happened it sent execution to the sub process, and it exited!
Is there something I am missing?
- I need the sub process to execute when the task is created - this will run business logic to sync task id to application
- I need the execution to resume at the task