Why Overtuning Can Be A Problem
Speed! Is that all we need for our software? I'm not sure why this concept is so popular. We benchmark everything this days, from the milliseconds that a function runs to how much time an Ajax call takes to return.
Of course we don't want slow apps or websites, but since this benchmark war began, we're so obsessed with tuning our code that we forget one important thing, the user experience.
We can easily lose a couple of hours tuning a function to gain some extra 10 or 15 milliseconds, but we forget to show a loading screen and feedback to the user in terms of what the software is doing.
After all, the user don't care if it took 115ms or 100ms to save his or her form, but he or she will care if they can't be sure whether it was saved or not.
I agree that we can't make software that takes forever to respond. Usually three seconds is not a long time for someone to wait, but 30 seconds is.
Just remember that: feedback > speed.