Adobe’s ambitious XD app has recently added a raft of new features, and here Khoi Vinh shows a compelling demo of instantly-updating artwork & on-device prototypes. (If for some reason the demo isn’t already queued to the right spot, jump to 8:21.)

A hardware glitch forced Khoi to (figuratively) tap dance during the first portion, and he offered a detailed peek behind the curtain, describing the demo team’s relentless pre-game preparation—and its limits. It’s so nice to see people really giving a damn.