Slack founder: Mental models for building products people love ft. Stewart Butterfield

Stewart Butterfield, co-founder of Flickr and Slack (sold to Salesforce), talks with Lenny Rachitsky about the product and leadership mental models behind Slack's success. The conversation covers utility curves, the difference between comprehension and friction, taste and craft, Parkinson's Law, hyper-realistic work-like activities, pivoting, generosity toward customers and employees, and the 'owner's delusion'.

01Key learnings

• Plot features on a utility curve to see whether extra investment is still on the steep part of the value gain or has reached diminishing returns.
• Judge a product by whether users understand what it does; in many places the real challenge is comprehension, not friction, so design for clarity over fewer clicks.
• Cultivate taste deliberately: taste can be trained, and leaning into craft can become a competitive advantage that less-attentive competitors leave open.
• Use small defaults and nudges to shape behavior, such as Slack's shouty rooster warning before @everyone, which also teaches users how the product works.
• Be coldly rational when deciding to pivot: exhaust the good possibilities, create emotional distance, and treat the decision as an intellectual one.
• Watch for hyper-realistic work-like activities; leaders must ensure there is sufficient known-valuable work so teams don't fill time with low-value meetings and analyses.
• Expect organizations to grow self-serving demand for headcount and work; counter it by making priorities clear and explicitly saying no upfront.
• Make your product's value obvious to newcomers by selling the outcome (the 'nail' or the 'horseback ride') rather than the feature (the saddle or the hammer).

02Frameworks mentioned

Summary and takeaways written by PM Atlas; quotes are short excerpts. © the original author.