From the website
"Educators will serve as Product Designers. They will apply and submit project ideas as a team of 2-3. Hackathon organizers will review all the ideas and select a few to be revised into a finalized project proposal ten days before the event. Our organizing committee will offer feedback to design teams to help ensure their ideas are technically feasible and appropriate in scope. The committee includes experts with Google Apps Script and members of the Google Apps Script developer relations team. See our page for teachers for more information.
"Programmers will apply together in Engineering Teams of 2-3. Prior to the event, engineering teams will be asked to indicate their top three choices of projects, and they will have the opportunity to join a Google Hangout with the Apps Script Developer Relations team for a one hour overview and Q+A on Apps Script. See our page for coders for more information.
"On the day of the event, engineering coders and product design teams will be paired together into a larger “Development Team” based on a match of interests and skills. The Development Team will work together on the day of the hackathon using their respective expertise to develop the proposed product."
Via Jim Lerman