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Matías Martínez Boylston

AI Direction

The Design System That Uses Itself

The promise at stake: adoption — the gap between "we have a design system" and "I know how to build my screen with it the right way."

Role
Head of UX — initiator and director of the initiative (directing agentic AI, not writing the code myself)
Context
Financial services; a design system and the product teams that consume it
Timeframe
2026, ongoing — a self-driven R&D bet

Outcome recap

  • A working proof that adoption — the hardest design-system problem — can be attacked from a new angle
  • One closed loop: build, self-check, and self-improve, instead of three separate tools
  • Accessibility scanning and prototype-building share the same machinery

The challenge

The hardest problem in a design system isn't building it. It's adoption. A system only returns its investment when product teams reach for it by default and apply it correctly — and the gap between "we have a design system" and "I know how to build my screen with it the right way" is where most of that investment quietly leaks away. Adoption work is unglamorous and chronically under-resourced; it rarely gets its own budget line. Meanwhile, every team that reinvents a component or misapplies a token erodes, screen by screen, the exact consistency the system exists to guarantee.

The conventional answer is more governance — police usage, review everything. That doesn't scale, and it breeds friction with the very teams you need on your side. Fighting adoption with enforcement just turns the design system into the thing product teams route around.

What I did

I wanted to invert the problem: instead of forcing adoption, make building it right the path of least resistance. That reframe was the idea, and I made the bet on my own initiative, rather than waiting for the adoption problem to get funded: an AI agent that prototypes faithfully to the system. You describe a screen in plain language; it produces a working, on-brand prototype built only from the real components and tokens. It's on-brand by construction, not by approximation, because it consumes the live design system the same way a real product team would.

The design decision that made it more than a demo was to make it a closed loop, not a one-shot generator: the agent builds from the system's real components and tokens, then checks its own work — screenshotting itself, reviewing against layout and brand rules, and running an automated accessibility scan before it's allowed to call anything "done" — and every correction persists, so it gets more accurate with use instead of repeating the same mistakes.

Plate 01 — The Closed Loop A single continuous cycle with three stages arranged in a triangle: Build, Self-check, and Self-improve, connected by one teal directional loop rather than three separate tools. A terracotta node at the center represents the persistence layer — the registry that every correction feeds back into, making the loop compound over time. Build Self-check Self-improve Persists registry
Fig. 01 — The Closed Loop. Build, self-check, and self-improve as one continuous cycle, not three separate tools.

Getting to a trustworthy self-check was the hard part, and it didn't work on the first pass. AI output is plausible-but-wrong by default — a prototype can look right at a glance and still misuse a component or fail contrast — so the self-check had to be strict enough to catch that, not just decorative. Making the agent actually look at what it built, against real rules, before declaring victory, is what turned a fast demo generator into something I could trust with real work.

The kicker: build and audit are one capability. The same accessibility scanning baked into the "done" check is the machinery that produced my WCAG accessibility report. "Build it right" and "prove it's right" aren't two tools; they're one loop. Every prototype the system generates is also a probe of what the design system gets wrong.

Plate 04 — The Shared Harness One core machinery box, labeled "Accessibility-scanning harness," branches into two outputs: "Build it right," an on-brand prototype, and "Prove it's right," the WCAG accessibility report. A terracotta node marks the harness as the single critical shared component — the same scan powers both outputs rather than two separate tools. Accessibility- scanning harness Build it right (prototype) Prove it's right (WCAG report)
Fig. 04 — The Shared Harness. The same accessibility-scanning machinery that checks a prototype's work also produced the WCAG audit report.

I used it as a real working tool, not a demo prop — for example, to turn an ambiguous product spec into a clickable, state-by-state prototype that an internal product team could react to, moving a conversation from a document full of "TBD" to something tangible they could click.

Artifact · Working Playground Demo — Coming Soon

Outcome & impact

A working proof that the hardest design-system problem — adoption — can be attacked from a new angle: make the correct path the easy path instead of policing the wrong ones. Production-looking prototypes from plain-language prompts, on-brand by construction and accessible by default, with one loop that both accelerates building and enforces quality — so velocity and rigor stop being a trade-off.

Artifact · Sample Prototype — Coming Soon

Plate 06 — AI Fluency at the Leadership Altitude A two-column contrast diagram mapped onto the build-check-improve loop. The left column, marked with a single terracotta node at its head, is "Directing and judging": setting the quality bar, gating output, and judging results at each of the loop's three stages. The right column, in plain ink, is "Prompting a tool": running the same three stages with no defined bar, no gate, and no judgment. The terracotta node is the leadership move; the ink column is the default. Directing & judging Prompting a tool Build Sets the bar Check Gates output Improve Judges results Build No set bar Check Ungated Improve No judgment Same loop, different altitude
Fig. 06 — AI Fluency at the Leadership Altitude. Directing and judging agentic AI toward a strategic problem, not prompting a tool or chasing a use case.

What compounds is the knowledge underneath it: a self-improving base about the system that gets more useful with every use, and is positioned to feed future AI tooling. Taken together, it's a demonstration of AI fluency at the leadership altitude — directing agentic AI toward a strategic problem, defining the quality bar, and judging the output — the opposite of an engineer hunting for a use case. It's already shaping how the team thinks about where the design system goes next.

What this taught me

The lesson wasn't the AI — it was the discipline of not trusting it. Plausible-but-wrong is the default failure mode of anything generative, and the only real defense is building the judgment in as a gate, not a hope. That's a leadership call as much as a technical one: deciding where the bar is, and refusing to ship until the system meets it itself. This was a self-initiated bet with no team behind it yet — which means the credit here is narrower and more personal: it's proof of what I choose to build when nobody's asked me to, and the same standard I'd expect from anyone I directed to do it.

"Plausible-but-wrong is the default failure mode of anything generative, and the only real defense is building the judgment in as a gate."

Skills demonstrated

  • Design-system strategy
  • Adoption and DesignOps thinking
  • Agentic AI direction
  • Prompt-to-prototype system design
  • Quality-harness and self-verification design
  • Accessibility automation
  • Knowledge-substrate (registry) design
  • Product prototyping
  • Technical judgment at leadership altitude

Proof / artifacts

The working playground, the closed-loop diagram, the shared-harness callout, and the sample prototype are shown above, in context.