[cle]

A contributor in this space that I always thought was under-appreciated is Amazon SWF + Flow Framework. It's an older technology and SWF itself is deprecated, but it is a weird middle ground here in that it makes language-level modifications to inject workflow state persistence and coordination into Java code (via AspectJ). The original concept was to build a "distributed CPU" (ex see https://docs.aws.amazon.com/amazonswf/latest/awsflowguide/aw...).

SWF was the predecessor for AWS Step Functions. IIUC the lesson learned from SWF was that it was just too flexible, and imposing a more limiting set of constraints was both easier for the programmer to use & reason about, and made for simpler and faster execution.