Catherine Williams

Chief Data Scientist, Xandr

Catherine Williams, Chief Data Scientist, Xandr

Like all ambitious academics, Catherine Williams worked hard and climbed her way up the Ivory Tower. After getting her PhD in math, she was admitted to a post-doctoral position at Stanford, and then another at Columbia.


She was highly successful—but knew she faced a crossroads. She liked teaching, and she loved math, but the more time she spent in academia, the more apparent it became that her first career path wasn’t for her.


Williams made an audacious decision: She’d seek a career in tech. The fact that she couldn’t really program didn’t bother her in the least. She taught herself JavaScript online, building a Sudoku puzzle solver and proving to herself that she could pick up the skills required to transition from the world of theory to the world of practice.


AppNexus was quick to see Catherine’s promise, and hired her as their chief data scientist, where she went on to lead a team of three dozen analysts and data scientists.


With the help of her team, she reimagined the company’s business as a marketplace, and created mathematical models that could track ad spend, what formats are ascendant, ebbs and flows in inventory supply, and other critical questions as she helped shape the company’s product and strategy, backed by hard numbers and keen insights.


After AppNexus’s merger with Xandr, Catherine became the company’s Chief Data Scientist, and continues towork on advanced technology and data products that enable advertisers to optimize campaigns effectively and publishers to manage and maximize yield. She is also a leader in the effort to continue and create a more diverse and empowering environment for women in tech.