A Chief of Staff (CoS) is a senior executive who works directly with the CEO to extend their reach and multiply executive bandwidth. The role coordinates across the leadership team, drives strategic initiatives that don't fit cleanly into a functional VP's scope, manages the executive's time and priorities, and prepares board materials and executive communications. Adopted from political and military contexts where it is well-established, the CoS role is increasingly common at venture-backed startups around Series B-C as the CEO's bandwidth becomes the limiting factor on company velocity. It is one of the most-misunderstood executive roles because the scope varies enormously by company, and the role works very well at some co...