The Model Is the Experience — Paz Perez

The core of your AI product is being designed without you. Engineering and product are shaping model behavior through system prompts, data decisions, and evaluation frameworks. These are design decisions. If designers are not involved, someone else is making them.

In AI products, the experience is no longer a static interface. It is generated in real time by models making decisions on behalf of users. Paz argues that this is the shift that redefines what UX work actually is: from designing interfaces to shaping behavior.

This talk introduces a new UX toolkit built around data, context, and evaluations, the materials that define what models know, how they respond, and what success or failure looks like. Paz shows how designers can move upstream, collaborate more effectively with product and engineering, and bring a user-centered lens to the decisions that shape AI behavior before anyone else has framed them.

About the speaker

Paz Perez,
AI Design Consultant at Nothing Fancy AI

Paz has led AI design solutions used by millions across the tech ecosystems of San Francisco and New York. At Google, she built the “Gen AI for UX Teams” program from the ground up, empowering hundreds of colleagues to confidently navigate and apply AI in their work.

She coined the term “Model Designer”, inspired by the early work of content designers shaping AI models. It became a new role in the industry, now with presence in companies like OpenAI, Figma, and Google.

She is at the forefront of defining how UX can influence how models behave. Before moving into UX, Paz spent 8 years as an architect designing public schools in New York City and Barcelona, an experience that shaped her ability to lead complex systems and create inclusive, culturally aware experiences. Now she lives in Southern Spain, where she co-founded an AI consultancy firm, Nothing Fancy.