Sebastian, you're right. And thank you for the care that went into this. A flat tree only works at the top of the ladder, which contradicts what I promised in Episode 2. I've adopted nested folders and updated the post, with your name on it. One thing I changed while adopting it. Your tree has orchestrate and core at the top level, but at the Minimum tier those live in Engineering, and a workspace can only bind one folder. So I shaped the tree after the three-layer floor instead: store, engineering (ingest, prepare, orchestrate, core) and analytics (model, present). That way a tier is only a choice of which folders get a workspace, and nothing ever moves. On the "user has to play along" part, I think you're being harder on the idea than it deserves. Whether an item is in its responsibility folder is just a path in the repo, so CI can check it on every commit. Someone can still put a notebook in the wrong place, but they find out the same day instead of on the day they scale up, and fixing it is a drag and a commit, not a migration. I've added that to the post as well. On "definitely not a migration" I agreed with one condition. It's only a rebind if the references were dynamic to begin with. Notebooks that resolve lakehouses by name, and pipelines and models whose references are resolved at deploy time, don't notice the split at all. Static IDs baked into definitions do, and those are the ones people have. So the folder layout makes scaling cheap, and designing for automation is what makes it free. Which is a decent summary of where this series is going. Good luck with your own version. Borrow whatever's useful. This is exactly the kind of feedback that makes the ideas better.

