[thebeardisred]

While not the best answer, I've used Jenkins extensively in the past for some rather creative purposes. Besides the standard "watch a SCM repo and react" type functions I've used it in combination with libvirt to spawn VMs self service for users (as well as coordinate the accounting and access control around this), watch an etag for a file to change in object storage and react, etc. I agree with some of the other commentary in that it's most useful aspects are around not using it with a traditional CI pipeline.