Yeah, the 'why' often literally doesn't exist as information in the code anywhere, e.g. business rules, domain-specific knowledge, etc. If you're extremely luck

Yeah, the 'why' often literally doesn't exist as information in the code anywhere, e.g. business rules, domain-specific knowledge, etc. If you're extremely lucky it might exist as 'why comments' :) I do wonder if ML could be applied if you actually also train it on your particular (large) application where if might be able to 'cross-reference' domain knowledge present in commented code to other similar code. (But then you might want to just remove the pseudo-duplication anyway.)