You won’t find SenseTime’s name on the building that houses its Beijing headquarters, but its technology guards the entrance. All workers must clear a security check by SenseTime’s facial-recognition software, and company employees pass a second face scan to enter their offices. In its entrance hall, SenseTime, a privately-held company now valued at more than $7 billion, shows off some of the products that made it one of the world’s hottest startups in artificial intelligence, and helped the company beat out Facebook’s facial recognition algorithm to become the most accurate in the world. By teaching computers to think like humans, AI technologies can replicate functions like speech, hearing and — SenseTime’s specialty — vision. A digital billboard in the lobby, for example, shows how SenseTime-enabled cameras placed in stores capture images of shoppers and then sort them by age and gender, creating valuable demographic data bought by retailers. On another screen,