Yes, I have. We used to call it "debugging", but I guess everything has to have a name before the cool kids will use it. However, this wasn't about find a bug

Yes, I have. We used to call it "debugging", but I guess everything has to have a name before the cool kids will use it. However, this wasn't about find a bug but preventing defects by using evidence to retrain my behavior. The approach is to assume nothing, then use simple graphs and data to look for places where you can change how you do stuff to improve your code. It's not hard, just really tedious.