> strategy where they burn one engineer by having them read the original code, have them document it carefully with a lawyer to remove all expressive aspects, and then have a separate engineer develop it from the clean documents.

Interesting. What kinds of situations is that strategy used for?

(I'm familiar with cleanroom, which I understand means that you start with un-tainted engineers, who've credibly never been exposed to the proprietary IP, the work only from unencumbered public documentation and running the system as an opaque box. Then there's also validation, like with parallel systems and fuzzing. But I haven't thought through in what situations this might not work, so might require the tainted documenting approach.)