Comment by StillBored

Yah, was going to say something like this. I've fixed these problems a few times, and I don't really think any of them were particularly hard. That is because if your the first person to look at something with an eye to performance there is almost always some low hanging fruit that will gain a lot of perf. Being the 10th person to look at it, or attack something that is widely viewed as algorithmically at its limit OTOH is a different problem.

I'm not even sure it takes an "experienced" engineer, one of my first linux patches was simply to remove a goto, which dropped an exponential factor from something, and changed it from "slow" to imperceptible.