Design patterns, OOP, to a large degree programming languages are just tools. You don't hear of craftsmen saying things like "The only thing you really need is

Design patterns, OOP, to a large degree programming languages are just tools. You don't hear of craftsmen saying things like "The only thing you really need is a hammer. It's been around longer than the other tools and you can use it on every project". Replace "hammer" with C or Java and you have a legitimate comment on a score of threads. > What patterns don't help with is the initial design of a system. In this phase, the only thing you should be worried about is how to faithfully and correctly implement the business rules and procedures. I submit that should be your overriding concern at all times, not just the design phase. If you have to refactor some code in order to extend it, tie it back to the changed requirement. This forces you to make the least amount of changes, refactoring the least amount code, breaking the least amount of unit tests and introducing the least amount of bugs into production.