I’ve been evaluating Bonita BPM for use at work and everything seems great other than the fact that our processes rely heavily on automated long-running actions.
Is there a way to implement custom functionality with a Service Task? There seems to be no mention of them in the documentation past 5.x.
What do you mean There seems to be no mention of them in the documentation past 5.x.
Custom Functionality or Service Task
Service Tasks are definitely in 6 and 7 and we definitely use them for custom functionality. 
regards
Seán
PS: If this reply answers your question, please mark as resolved.
Is there any chance you could provide me with a link? Searching the 7.2 documentation for “Service Task” (http://documentation.bonitasoft.com/search/site/Service%20Task) gives me a top result regarding performance tuning and further down a link which says only this:
A service task is carried out automatically by the Bonita BPM Engine and is invisible to users during normal operation.
A “custom functionality” search returns a variety of other types of customisation but nothing which looks like this as far as I can see.
Am I looking in the wrong place?