Diana Metsisto started her career as a programmer and systems analyst working on scientific, real-time systems. After 11 years she switched to education, where she worked as a 7th grade mathematics teacher for 23 years in Norwell, Massachusetts. She then served as a mathematics coach for three years under the auspices of the Massachusetts Middle School Mathematics Project. For the past two years, Diana has been a consultant for the Education Development Center, working as a coach with teams of middle and high school mathematics teachers for the Lesson Study Communities Project.