I don't think that holds true. 80/20 rule? Probably. Then 80% of CPU time is spent in 20K lines of code. But 1%? I don't think so. A web project of 100KLOC w

I don't think that holds true. 80/20 rule? Probably. Then 80% of CPU time is spent in 20K lines of code. But 1%? I don't think so. A web project of 100KLOC will be a shit ton of features and CPU time will be spent in hundreds of different places. Another issue is what I would call "code depth". Even if you find a few lines deep down in a framework or library that makes your specific use case slow - what can you do? Patch the framework? That comes with a ton of issues on its own.