First Stop Health is moving its coaches and therapists to a new EHR, and all of them have to switch on the same day. So designers built a working copy with Claude Code, and providers practiced on it before engineering built the real thing.
When you can't switch a few people at a time, you can't find a few mistakes at a time either. Every mistake would show up for every provider on the same day. So we found them first. Designers built a working copy of the new EHR in real code, and coaches and therapists used it like the real thing before engineering built it.
First Stop Health gives people care through their job: urgent care, primary care, and coaching and therapy. Each of those services keeps its notes in a different system, so a provider can't see the whole patient in one place.
This year we started moving all of it into one system, with coaching and therapy going first. Our data team needs every record in one place, which means we can't move a few providers at a time and fix problems as we go. Everyone switches on the same day, and if something is wrong, every coach and therapist finds out at once. I led design for the switch, and my job was to make sure the new tool worked for providers before that day came.
One switch day means one chance to get it right. So we built a working copy first and used it to find problems while they were still easy to fix.
A picture of a screen can't show what happens when a provider clicks the wrong thing. So designers built working screens with Claude Code that run in a browser and save what you type. They kept the code in GitHub, the same place engineers keep theirs, and checked in their work the same way. That meant engineering could start from screens real providers had already tried.
Before the prototype, we built the design system, one shared kit of buttons, forms, and layouts. That kit is what let Claude Code build screens that looked and worked like they belonged together.
Coaches and therapists clicked through real visits on the working copy, six sessions in all. We fixed things between sessions, so each one tested a better version than the last.
In six sessions, coaches and therapists found three problems that would have broken work they do every day. In all six, nobody could find how to reschedule a visit. In three, a provider booked the wrong time because of the time zone setting and didn't notice. In four, a provider couldn't get back to a visit after leaving it. All three were easy to fix in the prototype. If they had shown up on switch day instead, every coach and therapist would have hit them at once.
A personal AI with access to everything you'd never share. Lew Cirne, founder of New Relic, had email, calendar, GitHub, and Notion wired into one view. I joined to give it an experience, from the value proposition down to the type. The hard problem is the trust boundary: who may ask my assistant what, drawing on which of my data.
