Joseph (Joe) Yoder (agilist, computer scientist, speaker, and pattern author) is the founder and principal of The Refactory (www.refactory.com), a company focused on software architecture, design, implementation, consulting, and mentoring on all facets of software development. Joe is also the president of The Hillside Group, a non-profit dedicated to improving the quality of life of everyone who uses, builds, and encounters software systems. Joe is well-known as an author of the Big Ball of Mud pattern, illuminating fallacies in software architecture. Joe is a co-author of "A Scrum Book: The Spirit of the Game'' which includes 96 patterns for getting the most out of Scrum. Joe teaches and mentors developers on agile and lean practices, architecture, cloud, flexible systems, clean design, patterns, refactoring, and testing. Joe has presented many tutorials and talks, arranged workshops, given keynotes, and helped organize leading international agile and technical conferences.