I believe it's very common to find little variations on algorithms or coding style like this that could produce a nice gain in efficiency or elegance. They aren

I believe it's very common to find little variations on algorithms or coding style like this that could produce a nice gain in efficiency or elegance. They aren't really the same problem as whole-system engineering, though, since most of your bottlenecks come from the algorithm that is completely unsuitable, not the one that is a little bit suboptimal.