John has been a consultant, system administrator, university lecturer, and software engineer over the course of the past fifteen years; currently he is working at Chef to make Chef even more awesome than it already is. He has experience developing software for organizations ranging from small start-ups and government entities to Fortune 500s. He has previously authored two other books on managing systems using Chef. Matthias is a software engineer ""Made in Germany"" and the author of the Chef Infrastructure Automation Cookbook by Packt Publishing. His four children make sure that he feels comfortable in lively environments, and stays in control of chaotic situations. A lean and agile engineering lead, he's passionate about continuous delivery, infrastructure automation, and all things DevOps. In recent years, Matthias has helped build several web-based businesses, first with Java and then with Ruby on Rails. He quickly grew into system administration, writing his own configuration management tool before moving his whole infrastructure to Chef in its early days. In 2008, he started a blog (http://www.agileweboperations.com) together with Dan Ackerson. There they shared their ideas about DevOps since the early days of the continually emerging movement. You can find him on Twitter as @mmarschall Earl is a virtualization development professional with more than 10 years of focused industry experience, creating innovative solutions for hypervisor provisioning, management, and automation. He is an expert in aligning engineering strategy with organizational vision and goals, and delivering highly scalable and user friendly virtualization environments. With more than 20 years of experience developing customer-facing and corporate IT software solutions, he has a proven track record of delivering high-calibre and on-time technology solutions that significantly impact business results. Earl lives in San Diego, California. He is blessed with a beautiful wife, Patti, and three amazing daughters, Alexis, Daniella, and Madison. Currently, Earl is a senior software engineer with Intuit Inc., a company that creates business and financial management solutions that simplify the business of life for small businesses, consumers, and accounting professionals. Earl can be found online at http://sandiegoearl.com.