Fit in my head
Software should be simple enough to fit it's context in your head.
- Do the simplest thing that could possibly work, and iterate on the solution over time.
- Simple solutions reduce points of failure on a team where one a single person knows how something works.
- Hold each other accountable, if the majority of the team don't understand something its prime for refactoring.
Sometimes also known as "Do the simplest thing that could possibly work", we value systems that don't make us think to hard. The harder we have to think about software the more likely mistakes will be made in the future. This principle also encourages us to avoid being too "clever", a solution that seems elegant at the time that no one else understands is going to be hard to maintain.