“Why should we write our tests first? Isn’t that going to slow my development?” “What? Assigning a single task to 2 developers? How is that efficient? What a waste of resources!” “Look, in the perfect world your advises are great, but I have a project to finish here.” In this talk Marcello Duarte explores efficiency in contrast to effectiveness. He looks into how practices, traditionally accepted as efficient, sometimes turn out to be less effective than a few “impractical” things he has come across.