Founded in 2007 by Brian O'Kelley and Mike Nolet, AppNexus quickly established itself as one of the most innovative companies in the online advertising industry. Through its cutting-edge technology and its ability to offer real-time bidding (RTB) platforms, AppNexus redefined the programmatic advertising market. In 2018, it was acquired by AT&T for approximately $1.6 billion. For female entrepreneurs, the story of AppNexus provides valuable lessons on creating disruptive technology, sustaining growth, and adapting to a constantly evolving market.