The Agile Yorkshire Xmas Lightning Talks Competition in 2015 brought together eight amazing speakers, each presenting a 10-minute talk on a topic they are passionate about. The event was full of excitement, with audience voting and a strict time limit. This video, filmed during the 2015 competition, showcases one of the standout presentations of the evening. Enjoy this insightful talk! In this talk, Michael Crane, Principal Engineer at Hermes, introduces Test-Driven Development (TDD) and shares his passion for promoting it within the teams he manages. Michael explains the history and evolution of TDD, from its origins with mainframe programming to its adoption in modern agile practices. He outlines the key principles of TDD, such as writing tests before production code, keeping tests minimal, and ensuring code only passes the tests. Michael discusses the benefits of TDD, including simpler, cleaner code, shorter feedback loops, and better confidence in refactoring. He also highlights how TDD helps developers think more critically about their assumptions and the problem at hand. Finally, Michael encourages anyone new to TDD to give it a try, emphasizing how it can lead to more reliable, maintainable code.