I think of this as a cross spectrum (terrible, good enough, well done, overdone)

I've seen less production code and more discussions on code that focusses on opposite ends.

terrible readability and maintainability with extreme performance.

v/s.

terrible performance with overdone "design" abstractions.

OTOH, I've seen lot of production code that has good enough design, with well done perf and vice verse.

Not much talk about that stuff.