Designing Perplexity (lukew.com)

Henry Modisett, Head of Design at Perplexity, outlined how AI is forcing a rethink of product design in a talk at Sutter Hill Ventures. He framed the moment as a "macro novelty effect"—users are either encountering AI for the first time or rejecting it by instinct—and argued most software will soon embed AI the way it embeds connectivity today. That rapid, crowded pace means teams are only “two or three weeks” ahead of one another, and conventional product processes (PRD → design → engineering → ship) no longer fit. Instead Modisett advocates a cycle of strategic conversation, get-anything-working prototypes, pruning, design, ship, and observe—“prototype to productize” rather than “design to build.” Technically, designers must wrestle with non-deterministic systems, trajectory-based experiences (designing for models that will improve), and the primacy of speed as UX. Perplexity’s approach has designers working directly with engineers on prompts as a programming language, prioritizing product mechanics (game-design thinking: mechanics > dynamics > aesthetics) over polish. Natural language can expose powerful capabilities and hide complexity, but it trades off precision and discoverability, so opinionated interfaces that clearly communicate capabilities are critical. The talk highlights practical shifts: embrace rapid iteration, expect to build broad capabilities early, and treat interaction design as systems design for stochastic models.