I had a 300k LOC game that needed refactored and segmented into DAG assemblies for a composable engine to reuse in a few other similar games our studio is prepping to build.

I tried holding Opus's hand over a week trying to get it done with a ton of in-depth planning and manual course-correction, but it never got it to a state where it was "done" (kept struggling to differentiate between game content specific to that game versus game systems we'd want to reuse, and how to cleanly separate systems vs content when extracting).

Fable needed a little bit of hand holding but got it done in less than a day.