Mike Schroepfer is sitting in a conference room inside Facebook’s Frank Gehry-designed headquarters. His ultra-modern surroundings—22-foot ceilings, raw steel beams, polished concrete pathways that flow through acres of open desks—suit his responsibilities. Schroepfer, the company’s chief technology officer known around Facebook as “Schrep,” works on the stuff of science fiction. High-altitude drones that blanket swaths […]