China’s booming start-up scene has become as much a feature of its top-tier cities as traffic and smog. It used to be that college graduates applied for jobs at banks or state-owned enterprises, the proverbial “iron rice bowl” that their parents sought for them after the chaos of the Cultural Revolution. But many of those jobs were unsatisfying: In a 2012 Gallup survey, 94 percent of Chinese respondents said they were unengaged with their jobs. Now, with public and private funding flowing into Chinese start-ups, entrepreneurship has become an appealing alternative for a generation disillusioned with the conveyor-belt career paths of their forebears.