Refactoring is the process of taking existing code and improving it. While it makes code more readable and understandable, it also becomes much easier to add new features, build larger applications, and spot and fix bugs. In this course, staff author Simon Allardice introduces the formalized, disciplined approach to refactoring that tells you exactly what to look for in your code, and how to fix it, through a series of "code smells"—clues that let you look at a block of code and realize when there's something wrong with it.