
In this Y Combinator Startup School talk, Jake Heller, co-founder and CEO of Casetext, explains how his team stopped everything at $20M in revenue to build CoCounsel, the first AI assistant for lawyers, on early access to GPT-4 — a bet that led to a $650 million acquisition by Thomson Reuters. He lays out a practical playbook across three areas: how to pick an idea (target jobs people already pay for, in categories of assist, replace, or do the previously unthinkable), how to actually build reliable AI (map exactly what a professional does, turn each step into prompts or plain code, and grind on evaluations until you pass 97-99% of tests), and how to market and sell it (build a genuinely great product first, price to value, build trust with head-to-head comparisons, and watch out for pilots that never convert to real revenue).

Patrick Campbell bootstrapped ProfitWell (originally Price Intelligently) from a cashed-out 401k into one of the most cited SaaS pricing authorities on the internet, serving 30,000+ companies for free before selling to Paddle for $200 million in 2022. Known as @Patticus, he turned a debate scholarship, a stint at the NSA, and a barista certificate into a decade-long conviction that pricing is the most underleveraged growth lever in SaaS. Now living in Puerto Rico and quietly building a new healthcare company.