Content & Model Designer

Evals. Losses.
Instructions.
Repeat.

I define how AI communicates with people: its personality, how it sounds, what it shares, and how it makes you feel. I've led design teams at Meta and Huge, and now I am a model designer working on Gemini.

Jess L'Esperance

"When nothing is fixed and everything is fluid, guardrails and instructions are the experience."

I thrive in the in-between space, where the problem is still being defined and the stakes of getting it right are highest. That's where I do my best work, especially at 0 to 1.

I partner closely with researchers, engineers, PMs, and policy teams to get alignment on what good looks like before anyone writes a single instruction. In my experience, most model quality problems are actually design problems, and they happen upstream.

Every output is a signal. Every eval cycle is an opportunity to get sharper, together. I hold a high bar for what we ship: responses that are helpful, factual, and trustworthy aren't a nice-to-have, they're the whole point.

Latest essay

Evals. Losses. Instructions. Repeat.

That's what my sweatshirt says. It also happens to describe my entire job. I'm a model designer, a title that didn't exist five years ago and still raises eyebrows at dinner parties. It sits at the intersection of UX, prompt engineering, behavioral design, and something that doesn't quite have a name yet.

This is the first in a series about designing the user experience of AI.

Model design Prompt engineering Brand voice Persona definition Evaluation frameworks Vision setting 0–1 Workshop facilitation Design leadership INFJ

Selected case studies.

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Content. UX.
Model Design.

I came up as a travel writer and editor, drawn to how language shapes the way people understand the world. That led to a master's in information science, then interaction design, then content strategy, and eventually to the work I do now. The throughline has always been the same: how do we build things that actually serve the people using them?

If you've worked with me, you know I want to solve the whole messy problem. Defining the operating logic of LLMs turned out to be a natural extension of everything I'd already been doing, just further upstream, with higher stakes, and a lot more interesting failure modes.

Where I started
Travel writer, editor, student of human behavior across cultures. Language as a lens for understanding how people move through the world.
How I got here
Information science → interaction design → content strategy → model design. Each step was really the same question asked at a different level of the stack.
What I do now
Model designer on Gemini, focused on health and wellness, defining what LLMs can do to support people's quests to stay fit and take charge of their health.

Currently available for

  • Model design
  • Eval frameworks & LLM quality
  • Conversational architecture
  • Content strategy & systems

A few other things

  • 👟 Amateur shoe maker
  • 🏺 Mediocre ceramicist
  • ✈️ Travel junkie
  • 🎓 Teacher & mentor

Let's connect.

Reach out via email or LinkedIn, I'd love to hear from you.