"Facebook's founding is legend. In a Harvard dorm, Mark Zuckerberg invented a new way to connect with friends and the rest is history. But for the people who actually molded this great idea into a game-changing $300 billion company, the experience was far more tumultuous and uncertain than we might expect. Mike Hoefflinger was one of those Facebook insiders. As a computer engineer turned marketing innovator who worked with COO Sheryl Sandberg, Hoefflinger...