In Facebook's early days, employees sat in a circle, described the project idea they had and broke up into small groups. As the hackathon's popularity has grown, Facebook now relies on wikis to self-organize.

"Weeks before the night of the hackathon, employees post their project idea to the wiki with a description of it and the number of people the team is looking for," Keyani says. "Anyone in the company is allowed to join."

Keyani says the wiki is a simple method that works well for them because interest in the event is so high. If you have a small department, meeting face-to-face like Facebook did might be easier, he says.

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