With 20 million daily players, Zynga's FarmVille has taken social gaming into the mainstream. It matched the biggest game out there in size within 40 days of launching and is now three times the size of the No. 2 game. Behind the scenes Rajlich, 26, leads the engineering team, and one of its main jobs is handling technical issues stemming from FarmVille's unprecedented growth. "We have to deal with problems that no one else in social gaming has to deal with because the game's so big," he says. He joined Zynga as part of the acquisition of a small software company he co-founded called MyMiniLife. Its technology was later used in the creation of FarmVille. But there's nothing mini about his work anymore. --B.K.
NEXT: Engineer runner-up: Amit Singhal
Last updated July 09 2010: 1:19 PM ET