So 90% of programming is crap? (Sturgeon's law) Seriously though, there are plenty of developers who can cautiously evaluate performance as they go. It's just

So 90% of programming is crap? (Sturgeon's law) Seriously though, there are plenty of developers who can cautiously evaluate performance as they go. It's just that it's not a super common skill (nor is writing low level code, etc), but it exists and is happening all the time. Game devs for example.