Lots of schools teach CS and say "Code it first and fix it later". They call this preventing "Premature optimization". It's not totally wrong. But it's often

Lots of schools teach CS and say "Code it first and fix it later". They call this preventing "Premature optimization". It's not totally wrong. But it's often wrong. The world isn't writing it's first program. Code that's too slow has a performance bug. And like any bug, it's better and cheaper to catch it early than late. And you can't always use your own code. Eating your own dogfood is a reasonable idea but it can break the organization that is trying to fix and build the software. For example, if there's a bug in your new bug reporting system you'll lose the information that there's a bug and never fix it. And so on. The performance gains that chip makers have given us have been stolen by the software makers to make generating software cheaper and faster, rather than being passed on to the users to make systems more responsive. Yes, there's a user benefit to having more software quicker, but that isn't enough.