Model Designer

The mission of Thinking Machines is to build AI that extends human will and judgment. We are training frontier models with Inkling, developing Tinker to let people make models their own, and crafting interfaces that broaden human-AI communication. We believe the future worth building is human, and we're hiring people who want to build it.

As a Model Designer, you’ll shape how our models behave and feel, and how people experience working with them. Working alongside the researchers building these models, you might design: how a model reads intent, when it acts on its own, when it asks, and whether the person comes away sharper than they started.

You’ll hold several things in tension: pushing what our models can do, anticipating what someone is reaching for before they’ve fully said it, and keeping the person’s judgment at the center of the work. We’re looking for creative generalists who care deeply about design, technology, and the humans on the other side of each turn.

• Work closely with researchers to understand, predict, and shape model behavior, translating design judgment into training data, evaluations, and lasting changes in the models themselves.

• Design how our models collaborate: when to take initiative, when to invite oversight or feedback, and how to earn the trust to act on someone’s behalf over time.

• Build strong, thoughtful defaults that people can reshape around their own knowledge, preferences, and values.

• Partner with research, product, design, and engineering from the earliest questions and prototypes to develop interfaces that widen the channel between people and models, including live and multimodal interaction.

• Find creative ways to collect high-quality data, especially the tacit, hard-to-articulate knowledge people build through doing real work.

• Help define what good looks like, with evaluations that capture what people and models accomplish together.

• Identify and pursue improvements based on product sense, user feedback, quantitative insight, and the research roadmap.

• Move comfortably across disciplines and projects, staying close to the work from the first idea through the details of shipping.

Minimum qualifications:

• Clear communication, including the ability to explain complex technical concepts in writing.

• Demonstrated ability to understand users whose needs and contexts differ from your own, through work across varied populations, domains, or cultures.

• Several years of experience in a role focused on how people interact with technology, such as product design, UX research, content or conversation design, or model behavior work at an AI lab.

Preferred qualifications:
We encourage you to apply if you bring some of the following; we don’t expect anyone to bring all of them.

• Experience designing model behavior or personality, or influencing technical roadmaps in domains where quality depends on judgment and there is no single right answer.

• Experience shaping how models approach research, exercise judgment, express uncertainty, or reflect a coherent set of values.

• Hands-on experience with large language models, including writing and iterating on prompts, evaluating outputs, and building an intuition for why a model behaves the way it does.

• A portfolio or writing samples that show exceptional taste, craft, and clarity, ideally including work that shaped how a product or system communicates with people.

• A track record of taking ambiguous problems from framing to shipped results, working across research, product, and engineering.

• Experience designing and running experiments—qualitative studies, A/B tests, or model evaluations—and making decisions based on the results, including dropping ideas the evidence didn’t support.

• Comfort with quantitative analysis: you can read evaluation results, find patterns in data, and explain findings to both technical and non-technical audiences.

• A clear point of view on how AI should support human judgment, shown through your past work or writing.

• Location: This role is based in San Francisco, California.

• Compensation: Depending on background, skills, and experience, the expected annual salary range for this position is $300,000–$400,000 USD.

• Visa sponsorship: We sponsor visas. While we can’t guarantee success for every candidate or role, if you’re the right fit, we’re committed to working through the visa process together.

• Benefits: Thinking Machines offers generous health, dental, and vision benefits, unlimited PTO, paid parental leave, and relocation support as needed.