I mostly focus on "using stuff that won't break", and yeah "if it actually matters". For example, much to the annoyance of a lot of people, I don't typically u

I mostly focus on "using stuff that won't break", and yeah "if it actually matters". For example, much to the annoyance of a lot of people, I don't typically use floating point numbers when I start out. I will use the "decimal" or "money" types of the language, or GMP if I'm using C. When I do that, I can be sure that I won't have to worry about any kind of funky overflow issues or bizarre rounding problems. There might be a performance overhead associated with it, but then I have to ask myself "how often is this actually called?" If the answer is "a billion times" or "once in every iteration of the event loop" or something, then I will probably eventually go back and figure out if I can use a float or convert it to an integer-based thing, but in a lot of cases the answer is "like ten or twenty times", and at that point I'm not even 100% sure it would be even measurable to change to the "faster" implementations. What annoys me is that people will act like they really care about speed, do all these annoying micro-optimizations, and then forget that pretty much all of them get wiped out immediately upon hitting the network, since the latency associated with that is obscene.