Developers tend to ignore C in order of complexity calculations but customers don’t.

Game developers and HFTs seem to understand this, and very few regular devs I’ve interacted with do. I’ve seen customers say they switched to someone else for speed reasons. And I’ve worked on projects where the engineers were claiming this as fast as we can make it, and they were off by at least a factor of three.

We like to think that being off by 10 or 30% doesn’t matter that much but lots of companies run on thin margins and publicly traded companies’ stock prices reflect EBITDA, it matters. Particularly in the Cloud era, where it’s much easier to see how sloppy programming leads more directly to hardware cost excess (as opposed to already purchased servers running closer to capacity)

Those margins also mean you have to pick your battles. Most software is not as performance sensitive as video games or HFT.

I take an efficient market hypothesis on this. Obviously devs can make stuff faster, and they do where it matters, as can be seen in games and HFT. In other software it’s a discussion with product of trade offs.