As far as tests are a descriptor of the business logic, another really difficult part that is also omitted from this article actually figuring out who the perso

As far as tests are a descriptor of the business logic, another really difficult part that is also omitted from this article actually figuring out who the person in the organization that can authoritatively tell you what the business logic is can be really tricky. Sometimes that person no longer even exists. Simply writing tests that test that the existing code does what it does is not always productive.