A
Visual change, no new behaviour
main → gate → preflight → push
Design didn't hand off.
It
shipped.
Three designers took a wall-mounted family hub from zero to a device on the wall, in eight weeks.
8weeks, first commit to first homes
71%of the code I wrote was prototypes
377commits from the design team
17/53shipped specs are agent surface
Home. The morning glance, read from across a kitchen.
One screen, wherever family life happens. 1920 x 1080, landscape, mains-powered, never off.
Ten ways the agent can answer you.
A generated reply has no fixed layout, so we specified the shapes it is allowed to take. This is the catalogue we designed to, and it ships as a scenario library inside the product.
01
Voice lifecycleWake, listen, think, speak, complete. The full motion sequence.
06
Ordered mixed resultsReply and cards kept in the order they streamed in.
02
Action receiptA finished action, re-checked against local truth before it shows.
07
Safe fallbackA malformed response still renders something recoverable.
03
Choice requestDisambiguation. Which Alex did you mean.
08
Long scrollable resultTen cards and long content at constrained pad height.
04
High-risk confirmationDestructive action, with a local cancel path.
09
Error stateTerminal failure, with the transcript preserved.
05
Phone portalA result that continues in the phone app.
10
Non-blocking noticesBusy turn, audio-only degradation. Never a dead end.
Every state is reviewable on demand, including the ones a real conversation almost never reaches.
The prototypes are screens in the real app.
Not files. They ship inside the production binary behind a debug panel, so engineering reviews a running thing on real hardware.
58,423Prototypes, in the shipping app
8,939The pad app itself
7,115Agent skills and rules
7,910Everything else
Lines of code I inserted, by destination. 82,387 across 713 files.
One step, two treatments, both running on the device.
Voice enrolment, grid versus carousel. The scrubber on the right walks the flow, so a reviewer needs no build.
A control panel for the agent's interface.
Six voice states, driven by hand, no account and no network. Twenty more prototypes live in the mobile app, eight of them mine.
Design has commit rights.
I negotiated the access, then wrote the rules that made engineering willing to grant it. They are an executable agent skill, not a wiki page.
B
Real front-end work, no backend
branch → spec + prototype → PR → me
C
Touches data, sync, permissions, native
branch → PR → me + eng owner
The gates are mechanical, so nobody argues past one. Designers can write code; we cannot approve it.
The part worth talking about
We used agents to build an agent.
You cannot redline a generated screen
So we specify behaviour and boundaries: what it may write, what it must ask, what it does when unsure.
The spec became the interface
Skills and rule files. A decision written precisely enough is executable: agents route it, build it, refuse it.
The AI is a contributor
Of 7,380 commits in the repo. The bar moved from can you build it to can you decide it.
The bottleneck stopped being production. It became judgement.
Believed. Broke. Shipped.
Believed
The hub runs as whoever set it up.
Broke
A child's chore said created by Dad. That account leaves, the wall dies.
Shipped
A family-owned device identity. It asks who a list belongs to; it never guesses.
Believed
Check the voiceprint, then answer.
Broke
A device that silently refuses is not secure. Nobody debugs a threshold in a kitchen.
Shipped
It always answers. Recognition only resolves "me" and clears the lock.
Believed
A PIN on the pad keeps the kids out.
Broke
Twice. They watch you type it, and the lock's own settings sit behind it.
Shipped
Settings moved to the phone. The pad page has no controls at all.
The rule underneath: the wall does, the phone decides.
The marketing site, before and after.
Same company, two visual languages, about four months apart. Each window scrolls the whole page.
BEFOREProduct shot
Rounded sans, an uppercase claim, hardware on a table. Reads like a spec sheet with a family in it.
NOWParent Copilot
Warm paper, one sentence per screen, video set inside the headline, the device shown in rooms. Sells a feeling.
What changed.
The function
Design became a shipping team.
Three designers, 377 commits into the product repo. The routes and review ownership are written down, so the model survives me.
The product
0 to 1 hardware in eight weeks.
First commit 27 June, v1.0.0 in first homes by late August. 53 specs, 579 commits on the device app.
The method
A repeatable way to design agent products.
Prototype inside the binary. Specify behaviour, not layout. Write decisions precisely enough for agents to execute.
Three things I got wrong first.
I optimised for output before judgement.
With agents, making things stopped being the constraint. I made more options than the team could evaluate.
I defended designs I had already finished.
The welcome animation, the pairing flow, the on-device PIN. The demo was fine. The kitchen was not.
I asked for capacity when I needed permission.
What unblocked the team was write access plus a rule set strict enough for engineering to accept.
It is early. The hub is with first families; the retention numbers do not exist yet.