Imran Khan was an internet-focused investment banker at Credit Suisse, where, in September 2014, he orchestrated Chinese ecommerce giant Alibaba’s high-profile IPO. Three months later, his star rose higher when he was named Snapchat’s first chief strategy officer, charged, many observers figured, with prepping the tech darling for its own eventual IPO. But in fact, Khan’s marching orders from CEO Evan Spiegel at the outset were more fluid than one might imagine.