[dekhn]

I wrote my own because I wanted to learn about DAG and toposort and had some ideas about what nodes and edges in the workflow meant (IE, does data flow over edges? Or do the edges just represent the sequence in which things run? Is a node a bundle of code, does it run continuously, or run then exit?). I almost ended up with reflow, which is a functional-programming approach based on python, similar to nextflow, but I found that the whole functional approach to be extremely challenging to reason about and debug.

Often times what happens is the workflow engine is tailored to a specific problem and then other teams discover the engine and want to use it for their projects, but often need some additional feature, sometimes which completely up-ends the mental model of the engine itself.