Butterfield's belief, central to how Slack made major design decisions: a static mockup can't tell you whether a design will actually work — you have to build a working prototype and use it to feel whether it works. Quote: "I can't tell you if this is going to work, I have to feel it, I have to try it."
This became a shared mindset across product, design, and engineering: write fast, throwaway code purely to learn, before committing to production work — treating the speed of disposable prototyping as ultimately faster than skipping straight to production. The mindset only works if engineering infrastructure is built to support it: Slack's old mobile app architecture was heavy enough that it blocked fast prototyping until it was redesigned specifically to make rapid, throwaway builds cheap.
See 'Everything Behind One Button' Prototyping Exercise for a concrete instance of this mindset in practice. Related to Prototype-Driven Persuasion and Rapid Multi-Fidelity Prototyping, but this concept is specifically about the causal claim that mockups are insufficient for judgment and the org-wide mindset/infrastructure required to act on that claim.
Из тем: The Product Operating Model