I don't think unreadable skills implies proper engineering at all. It's just as or more likely that they're the result of a blind iterative process with no clear improvement signal. (And whether iterative RL over a set of evals is actually proper engineering here is another question...)
> And whether iterative RL over a set of evals is actually proper engineering here is another question...
I'd put it like this: it at least demonstrates possession of the advanced skills expected of experienced software engineers.