Others have said touch typing. That is a given, but I don't think the speed matters once you get over a baseline (and yes, I say that as a relatively slow touch

Others have said touch typing. That is a given, but I don't think the speed matters once you get over a baseline (and yes, I say that as a relatively slow touch typist). I would extend it to be able to touch type your IDE of choice (which should be a Jetbrains product, if possible), by which I mean be able to use the shortcuts without having to think about what they are. If you think something should be refactored, you should already be selecting which methods to move to a superclass. If you need to rename a function, you should spent 100% of your effort on coming up with the name and 0% on navigating your IDE.