This is a lookback on a Y Combinator discussion regarding the burgeoning field of vertical AI agents. The speakers argue that these agents, which automate specific business functions, represent a market far exceeding that of Software as a Service (SaaS), potentially creating hundreds of billions of dollars in value. They draw parallels to the SaaS boom, highlighting how initially overlooked opportunities led to numerous successful companies. The discussion explores the potential for vertical AI agents to replace entire teams, focusing on identifying repetitive, administrative tasks as ideal targets for automation. Finally, the speakers provide examples of successful vertical AI agents already making an impact across various sectors.