about the authors

David A. Black is a well-known Ruby programmer, trainer, speaker, author, and event organizer. He was one of the founders of Ruby Central, Inc., the parent organization of the annual international RubyConf.

Joseph Leo III is the founder and owner of Def Method, a New York City-based Ruby on Rails consultancy dedicated to building high-quality, thoughtfully crafted software. He has more than 20 years of experience as a software developer, engineering leader, and Ruby community organizer.