Rethinking the process
We built the design system before we built the product for the same reason building was viable at all — the economics had changed. A few years ago that would have been overengineering, and the reason it isn't anymore is one of my most valuable takeaways from this project.
The team was three full-stack engineers who leaned backend, and me as the only product designer. Nobody to hand a redline to, nobody to absorb UI churn. By the old math, a full design system before an MVP is premature investment. You don't know what you need yet, half the components get thrown away, and a small team burns runway on polish before it has proof anyone wants the thing. That's the whole reason "ship the ugly version first" became default advice.
Building with AI
What changed is the cost of quality. With coding agents implementing against a defined system, a well-specified component is close to as fast to ship as an improvised one. The expensive part stopped being the building and became the deciding: what the component is, how it behaves, what it's called, what it does in every state. That's the part a model can't do for you, and it's exactly where a designer is already strong. And the reverse holds too: without a system to point at, an LLM will cheerfully generate a slightly different button forty times, every screen locally reasonable while the whole product is disjointed. A design system isn't overhead on top of AI-assisted development, it's what makes the output coherent.
So we built it first in Figma, using Figma MCP to connect Claude Code directly into the library, with Code Connect providing the mapping layer, so a component defined once is what the engineers actually get in code. The team spent far less time on frontend UI and could focus on backend and business logic, which is what they wanted to be doing anyway.
AI-developed, human-designed
The path from there was conventional even if the tooling wasn't. Wireframes first, to iterate early with the clinical and operations teams on what they actually needed. Then pixel-perfect mockups built on the system, with interactive prototypes covering real use cases end-to-end for user testing.
Polish isn't vanity in healthcare. There's an enormous amount of information in a clinical model, it's easy to hit information overload, and a poorly designed platform is exhausting to work in even when the workflows underneath it are right.