Mental models within an industry, company, or even a person, change constantly. As methodologies mature, we see the long term effects our choices have wrought and can adjust accordingly. As a team or company grows, methodologies that worked well for five people may not work as well for 40 people. If all employees could keep an entire app in their head, we’d need fewer rules and checks and balances on our development, but that is not the case. As a result, we summarize things we notice have been implicit in our work.