At a financial firm where I taught and coached ATDD and TDD, here’s the results as reported by one team: “One of the critical success factors for our project was our adoption of ATTD and TDD, including frequent test collaboration, engaging the business in writing acceptance test criteria, and robust test automation.” “Collaborating on writing tests ensured that the entire team understood all stories, which facilitated swarming and cross-skill development. We got questions answered real-time from the business that used to occur in one-off conversations and cause system test failure rework. We saw dramatically reduced failures during exploratory tests which further stabilized velocity. We added 0 manual test cases to our regression bed, and had high quality in production.”