David W Millar is a veteran software craftsman who holds a degree in computer science from Drexel University. He has had the pleasure of working in a wide variety of environments from small start-ups and research groups to industry giants such as IBM and Comcast. He is an active member of the Philadelphia tech scene and a contributor to the Groovy ecosystem. In his free time, he can be found hacking on open source projects; eagerly following tech trends such as the container revolution, IoT, DevOps, and infrastructure automation; or playing with his cats.

Pietro Martinelli is a software engineer, who has been working in enterprise application development since 2003. In 2002, he received his degree in computer engineering at the University of Brescia with highest honors. His main technical interests are languages development (primarily parsers and code generation tools development), enterprise application design, build and deployment automation, and quality-oriented development methodologies. He's an object orientation and testing bigot who loves teaching and mentoring students and colleagues on software design and testing methodologies. He writes about his technological experiences and his technical vision of the world in his blog, Java Peanuts, http://javapeanuts.blogspot.com.

Jason Winnebeck is a full-stack software developer with both frontend and backend development experience, including 15 years of experience with Java technologies and 4 years' experience with Groovy, specifically. He holds a master's degree in computer science from the Rochester Institute of Technology. He is married with two children, and enjoys volleyball and traveling.