Pipelines as programming method
Structuring your code in the shape of pipelines seems to alleviate a a lot of problems. I am using promise chains in javascript in this way as we speak. Or I speak. Or write, rather.
With these thoughts in mind, I look back at all my failures at reusable code and notice something else: It looks nothing at all like: source → algorithm → sink. In fact, it looks like a bunch of nested loops. The source data enters at the top, and gets swirled around and around in ever smaller and tighter loops, and leaves via the sink in the center of that maelstrom.