Stewart Butterfield — Co-founder, Slack & Flickr

**Stewart Butterfield** is a serial entrepreneur who co-founded both **Flickr** (sold to Yahoo for ~$25M in 2005) and **Slack** (sold to Salesforce for $27.7B in 2021). A philosophy major from the University of Victoria with a master's from Cambridge, he built two of the most iconic products in internet history — both of which emerged as pivots from failed video game projects. Flickr came from Game Neverending, and Slack came from Glitch.\n\nStewart's genius is recognizing when the side project is the real product. He also wrote one of the most celebrated internal memos in startup history — 'We Don't Sell Saddles Here' — which articulated that Slack wasn't selling a messaging app but a transformation of how people work. His product thinking focuses on emotional resonance, delightful details, and the gap between what users say they want and what actually changes their behavior.\n\nNo direct relationship with Josh Baer or Capital Factory documented.