> I’ve seen people say this kind of code was written, but I’ve never seen this kind of code anywhere I have ever worked.

Luckier than me. I've worked at a few places where the code was simultaneously brilliantly written[0] and also unmaintainable nonsense that caused endless problems. One place had its own object model and ORM that absolutely no-one currently at the place understood and literally every bug filed (whilst I was there) could be traced back to that code.

(Probably just a coincidence that most of those places where Perl shops but I've seen it with Go too...)

[0] In terms of "cleverness", not in terms of "maintainability" or "readability".