Applications often spiral down into big balls of mud and spaghetti code. Onboarding new team members becomes difficult and requires lots of mentoring and handholding or lots of digging on behalf of the new person. New features become difficult to add. Existing team members have trouble reasoning about the system. What steps can we take to mitigate some of these common pitfalls? In this session we are going to discuss several things we can do to avoid these problems and take a look at some real world examples. I will cover what I consider the 3 pillars of code design and how they should always drive your decision making as you design the internal structure of your applications.