Senior UI/UX Designer: Prototyping AI-Driven Interfaces

Mercor; San Francisco (CA); On-site; USD 140,000 - 180,000; Full time

Job summary

Cincinnatus LLC is seeking a senior product designer and design-minded engineer to help shape how an AI lab's UI/UX looks for the web and games, and to build prototypes that prove the ideas. You will work directly with researchers to define great design and to demonstrate it with high-quality prototypes.

This full-time role requires prototyping in code or AI tools and the ability to justify design choices. 40 hours/week with a W-2 placement at the lab.

Qualifications

• 7+ years of experience as a product designer, design lead, design engineer, or creative front-end engineer at a product- or design-led company.
• Hands-on prototyping skills: you build working web prototypes yourself, in code or with AI-native tools.
• Strong grounding in user-centered design, interaction design and rapid prototyping.
• Senior-level design judgment, and the confidence to set direction and explain why a design works.
• Ability to engage reliably for 40 hours/week during weekdays.
• Clear written communication and the ability to give precise, constructive design feedback.

Responsibilities

• Partner with AI researchers to identify best-in-class UI/UX patterns and define standards.
• Build polished, interactive web prototypes in code or with AI tools showcasing design patterns.
• Review AI-generated interfaces and provide actionable feedback on layout, motion and polish.
• Explore a range of visual styles and animation approaches for various product categories.
• Collaborate with designers and researchers to raise the quality bar.

Skills

Prototyping

User-centered design

Design leadership

Senior design judgment

Clear communication

Education

7+ years product design experience

Tools

HTML

CSS

JavaScript

React

Tailwind

Cursor

v0

Lovable

Bolt

Framer

Job description

Cincinnatus LLC is seeking a senior product designer and design-minded engineer to help shape how an AI lab's UI/UX looks for the web and games, and to build prototypes that prove the ideas. You will work directly with researchers to define great design and to demonstrate it with high-quality prototypes.

This full-time role requires prototyping in code or AI tools and the ability to justify design choices. 40 hours/week with a W-2 placement at the lab.