The Importance of Rendering

I've seen people post things about their engine that is rendering a certain amount of things, but rendering is only one part. And it can get really complicated. So many things can sort of bring it down. I don't know if I told this story before, but also related to the degree to which things are specified. But when Java decided to change that, people had to build and compile and test and they found out that things were broken because that.