Good news! Here’s video 11 in our series designed to jump-start your understanding of the core principles and practices of Agile Software Engineering (ASE). In this installment, one of our Lean-Agile thought leaders, Ken Pugh, talks about test-driven design. As we learned in video seven, Behavior-Driven Development (BDD) is about the triad of customer, developer, and tester writing story tests from a point of view external to the application. Test-Driven Development (TDD) is about figuring.