He sold his 8-figure business to bet on a side app—then grew it to 20x in a year. | Andrew Antos, Co-Founder & CEO of Within

Andrew spent two and a half years selling AI contract review to lawyers. It stalled at $800K. He rebuilt the company around finance teams and grew that to $10M. Then he demoed a little internal tool on the side at his own conference, and nobody wanted to talk about anything else. It did $350K in five weeks. He sold the $10M business and went all in on the side tool—Within went from zero to nearly $20M in 18 months.In this episode, Andrew breaks down the 30-and-100 rule he uses to validate every idea, how he turned every customer conversation into a database that tells him what to build next, and why nine out of ten experiments have to fail.Why You Should ListenWhy 30 conversations validate an idea and 100 customers reveal product market fit.Why the thing everyone asks about matters more than the thing you launched.How to tell that slow growth is a market problem, not a go-to-market problem.How to run four bets a quarter with a kill metric on every one.Keywords startup podcast, startup podcast for founders, product market fit, finding pmf, Within, Klarity, Andrew Antos, enterprise AI, AI transformation, pivoting a startup, enterprise sales, legal tech, finance automation, AI agents, customer discovery, voice of customerChapters00:00:00 Intro00:02:04 The Side Tool Everyone Wanted00:04:26 $350K in Five Weeks00:05:42 AI for Lawyers Before AI Worked00:12:44 Stuck at $800K00:13:43 Choosing Finance Over Legal00:17:40 The 30 and 100 Rule00:24:59 Selling the $10M Business00:32:17 Building a Company Data Brain00:40:01 Nine of Ten Bets FailSend me a message to let me know what you think!