Fabian Kreutz - TDD - the why, the how and the when not [EuroPython 2015] [23 July 2015] [Bilbao, Euskadi, Spain] TDD is great, we all know that. But why is it so, and under which circumstances is it ineffective or even harmful? In this talk I want to delve into the deeper meaning of testing to derive how to do it best. All of this from the point of view of somebody who has profited but also struggled with testing and TDD. For every experience level from beginner to advanced there is something to learn or ponder.