Computer architectures encompass 13 orders of magnitude of performance! That’s roughly the difference between something like a trivial function call processing data in L1 cache to a remote call out to something in another region. People often make relatively “small” mistakes of 3 or 4 orders of magnitude, which is still crazy if you think about it, but that’s considered to be a minor sin relative to making the architecture diagram look pretty.

It's easy to accidentally perform expensive operations in software systems.

If we can delete a single unnecessary 109109 operation, that pays for a lot of unnecessary 105105 order operations.

Optimize for the higher order of magnitude.