Personalized learning is in vogue. This is not lost on edtech startups. Dozens of apps are being built to help instructors personalize learning. But there are a group of engineers that have a leg up on all the other edtech developers out there. These engineers code at AltSchool and rather than coding in a vacuum, they work hand in hand with the teachers that use the apps. Together the AltSchool team of coders and educators measure the effects of their in-house apps, correct changes that aren’t positive, and propagate those that are good to get the maximum benefit. What is AltSchool’s ultimate goal? To provide “an operating system for a 21st century education.” Wired’s Issie Lapowsky tells the origin story of this small Silicon Valley experiment and how it’s about to get much bigger.