There is I think a large percentage of engineers like this that are insecure and like people having the reaction you are having and acknowledging how good they

There is I think a large percentage of engineers like this that are insecure and like people having the reaction you are having and acknowledging how good they are at understanding complex code. The most effective way to handle this type of person is usually to make it clear you respect their intelligence/are impressed by them, and then to ask them if they can try to apply that same intelligence to a different problem: as near universal legibility as possible. Trying to minimize context required for understanding code and think about how to put that map in their head in the code explicitly and to get as close as they can to universal language is a really really fascinating and difficult problem to try to solve, and even more impressive to see done. If they listen to that and get it that type of engineer can transform and start to write fantastic, very legible code. It think it depends on the type of intelligence they have, as well. In my experience there’s also a large percentage of people like you’re describing that are much better mathematically and visually/spatially than verbally. Sometimes this type of programmer is just better suited to writing the parts of a system that need to be very complicated. Some code is not really possible to write legibly without a bunch of prerequisite internal knowledge, like the deep guts of a game engine, some very complicated computer vision algorithm, etc. Having them stick to that stuff and make overview documents/general comments about whats going on can also be a good way to utilize their skill without as many downsides and illegibility problems.