Lenny Rachitsky @lennysan

Stewart Butterfield (@stewart) rarely does interviews. After 2 years of trying, I finally convinced him to come on.

In this special conversation, Stewart shares the frameworks and mental models that most helped him build two of the most important products in tech history (@Flickr, and @SlackHQ—which he sold for $28B, and which powers how basically every company collaborates these days).

We discuss:
🔸 "Utility curves" — his framework for prioritizing ideas
🔸 "The owner's delusion" — why restaurant websites suck
🔸 "Tilting your umbrella" — a hilarious Slack core value
🔸 "Hyper-realistic work-like activities" — my new favorite concept
🔸 "Don't make me think" — Stewart's foundational design philosophy
🔸 The story behind "We don't sell saddles here"

Listen now 👇
• YouTube:
• Spotify:
• Apple:

Thank you to our wonderful sponsors for supporting the podcast:
🏆 @WorkOS — Modern identity platform for B2B SaaS, free up to 1 million MAUs:
🏆 @getmetronome — Monetization infrastructure for modern software companies:
🏆 @Lovable — Build apps by simply chatting with AI:

Nov 20, 2025 View on X →

https://x.com/lennysan/status/1991568185519403029