Kyle Griffin has 25 years of experience as a programmer, process improvement specialist, and teacher. His extensive knowledge of programming includes C/C++, Android/Java/Groovy, and Python. He has been teaching and implementing XP programming practices since before the Agile Manifesto was written. In the last 10 years, he has worked variously as a lead programmer, agile coach, and trainer/mentor. Because of his forty thousand hours spent teaching and his experience as a programmer, he understands deeply the importance of taking a hands-on approach in the classroom. For fun away from work, Kyle writes android education software and treatises on the theoretical foundations of Agile methodologies.