Following the keynote is a Shout Out. If you are a participant, you are allowed 90 seconds to introduce yourself, share a little about yourself, your vision for an app, and make appeal for teammates if that is what you want to do. At the end of the time allotted to the Shout Out, all teams are finalized, and then the coding begins.
Typically, one team of two individuals may be looking for a second coder with particular strengths. Or a person with strong coding ability may be seeking a graphics person. This is the time they match up.