Cathy O’Neil is a mathematician, blogger, and author who became one of the best-known critics of unaccountable algorithms. She holds a PhD in mathematics, worked as a quant in finance during the 2008 crisis, and later founded ORCAA, an algorithmic-auditing firm. On her own site she frames her driving question as “what can a non-academic mathematician do that makes the world a better place?”
She is best known for the 2016 book “Weapons of Math Destruction,” which argues that many scoring and ranking systems used in hiring, lending, policing, insurance, and education share three dangerous traits: they are opaque, unregulated, and hard to contest. Because such models run at scale, she argues, they quietly amplify existing bias and lock in inequality while presenting themselves as objective math. The book won the Euler Book Prize and was longlisted for the National Book Award.
O’Neil’s later work, including the book “The Shame Machine,” continues her focus on how data systems exert power over ordinary people. For a general reader, she is a clear, accessible entry point to the idea that an algorithm’s fairness depends not on the cleverness of the math but on transparency, auditing, and the ability of affected people to challenge a decision.