Kent Beck is the creator of Extreme Programming (XP) and a pioneer of Test-Driven Development, pair programming, and the Agile Manifesto. A programmer with 52+ years of experience, he co-created JUnit with Erich Gamma, co-invented CRC cards and design patterns in software with Ward Cunningham, and spent seven years coaching at Facebook. Today he runs the 'Software Design: Tidy First?' Substack newsletter (123,500+ subscribers in 195 countries), hosts the Still Burning podcast, and explores augmented human-AI coding. In April 2026 he publicly announced a Parkinson's disease diagnosis, continuing his mission to help technologists feel safe in the world.
Michael Feathers is a software consultant, author, and Chief Architect at Globant whose 2004 book 'Working Effectively with Legacy Code' redefined how developers think about untested code - coining the now-universal definition that legacy code is simply code without tests. With over 25 years consulting hundreds of organizations, he pioneered dependency-breaking techniques that gave teams a way into codebases they feared. Today he explores how AI reshapes programming, writes the 'mechanisms' newsletter on Substack, and continues speaking at conferences worldwide.