The internal AI tool that’s transforming how Stripe designs products | Owen Williams

Stripe design manager Owen Williams built Protodash, an internal AI-powered prototyping platform that lets designers and product managers create high-fidelity dashboard prototypes without writing code. The tool, which evolved from Cursor rules and React components into a full web-based studio running in dev boxes, has been adopted equally by PMs and designers, fundamentally changing how the company approaches design reviews and engineering handoffs.

Owen Williams is a design manager at Stripe who built Protodash, an internal AI-powered prototyping platform that lets designers and PMs create high-quality Stripe dashboard prototypes without writing code. What started as a bundle of Cursor rules and React components evolved into a full web-based prototyping studio that runs in dev boxes, complete with design review modes, variant testing, and AI-powered iteration. Surprisingly, PMs now use Protodash just as much as designers, fundamentally changing how Stripe approaches prototyping, design reviews, and engineering handoffs. Listen or watch on YouTube, Spotify, or Apple Podcasts What you’ll learn: How Stripe built an internal AI prototyping tool using Cursor rules, MCPs, and their design system Why “blurple slop” happens when designers use generic AI tools—and how to fix it The architecture behind Protodash: React router, design system components, and MCP integrations How Stripe prototypes in dev boxes so designers never have to worry about local setup Why “demos, not memos” transformed Stripe’s design review culture How Stripe built design review modes, variant testing, and AI annotation directly into your prototyping tool Why internal tools don’t need to be production-grade to be transformative Brought to you by: Celigo —Intelligent automation built for AI Cursor —The best way to code with AI In this episode, we cover: 00:00 https://www.youtube.com/watch?v=hQFEAZK q0 Welcome and intro to Owen Williams 02:19 https://www.youtube.com/watch?v=hQFEAZK q0&t=139s The “blurple slop” problem with AI design tools 03:50 https://www.youtube.com/watch?v=hQFEAZK q0&t=230s Protodash: an internal vibe-coding tool for Stripe prototypes 05:26 https://www.youtube.com/watch?v=hQFEAZK q0&t=326s Why an engineering background helped Owen lower the bar for designers 07:55 https://www.youtube.com/watch?v=hQFEAZK q0&t=475s The Cursor rules that taught the Stripe design system 09:04 https://www.youtube.com/watch?v=hQFEAZK q0&t=544s Running prototypes on dev boxes vs. locally 10:30 https://www.youtube.com/watch?v=hQFEAZK q0&t=630s “Demos, not memos” and rewiring design reviews at Stripe 14:50 https://www.youtube.com/watch?v=hQFEAZK q0&t=890s Building Protodash Studio: a browser-based wrapper for prototyping 19:04 https://www.youtube.com/watch?v=hQFEAZK q0&t=1144s Live demo: variants, line charts, and remixing prototypes in browser 21:02 https://www.youtube.com/watch?v=hQFEAZK q0&t=1262s Self-testing prototypes that take screenshots and check their work 23:20 https://www.youtube.com/watch?v=hQFEAZK q0&t=1400s Multiple variant features 26:08 https://www.youtube.com/watch?v=hQFEAZK q0&t=1568s The annotate-for-AI button for in-canvas feedback 27:21 https://www.youtube.com/watch?v=hQFEAZK q0&t=1641s Design review mode: comments, summaries, and AI follow-up 29:39 https://www.youtube.com/watch?v=hQFEAZK q0&t=1779s Why building internal tools beats buying off-the-shelf 32:50 https://www.youtube.com/watch?v=hQFEAZK q0&t=1970s PMs as the surprise power users of Protodash 35:20 https://www.youtube.com/watch?v=hQFEAZK q0&t=2120s Live demo: a Black Friday/Cyber Monday pet store dashboard 42:03 https://www.youtube.com/watch?v=hQFEAZK q0&t=2523s Lo-fi modes, monospace fonts, and “Comic Sans for WIP” at Shopify 44:45 https://www.youtube.com/watch?v=hQFEAZK q0&t=2685s Quick recap 45:35 https://www.youtube.com/watch?v=hQFEAZK q0&t=2735s The Radar prototype that changed engineering handoff 49:08 https://www.youtube.com/watch?v=hQFEAZK q0&t=2948s Lightning round and final thoughts Tools referenced: • v0: https://v0.app/ https://v0.app/ • Cursor: https://cursor.com/ https://cursor.com/ • Claude Code: https://www.claude.com/product/claude-code https://www.claude.com/product/claude-code • Claude Design: https://www.anthropic.com/news/claude-design-anthropic-labs https://www.anthropic.com/news/claude-design-anthropic-labs • Figma: https://www.figma.com/ https://www.figma.com/ • Stripe Radar: https://stripe.com/radar https://stripe.com/radar • Balsamiq: https://balsamiq.com/ https://balsamiq.com/ Where to find Owen Williams: Website: https://owenwillia.ms/ https://owenwillia.ms/ LinkedIn: https://www.linkedin.com/in/owenpwilliams https://www.linkedin.com/in/owenpwilliams Where to find Claire Vo: ChatPRD: https://www.chatprd.ai/ https://www.chatprd.ai/ Website: https://clairevo.com/ https://clairevo.com/ LinkedIn: https://www.linkedin.com/in/clairevo/ https://www.linkedin.com/in/clairevo/ Production and marketing by https://penname.co/ https://penname.co/ . For inquiries about sponsoring the podcast, email email protected /cdn-cgi/l/email-protection .