Senior Product Designer: AI UI Prototyping Leader

Obsidian; San Francisco (CA); On-site; USD 180,000 - 230,000; Full time

Job summary

Cincinnatus LLC is seeking a senior product designer with exceptional taste to shape how AI models design for the web and games. You’ll build high-quality prototypes and work closely with researchers to define great UI/UX patterns.

The role requires 7+ years of experience, strong prototyping skills in code or AI tools, and the ability to dedicate 40 hours per week. This is a full-time W-2 engagement with potential placement at a leading AI lab.

Qualifications

• 7+ years of experience as a product designer or design lead.
• Hands-on prototyping in code (HTML, CSS, JavaScript, React, Tailwind) or AI tools.
• Strong grounding in user-centered design and rapid prototyping.
• Senior-level design judgment and ability to set direction.
• Ability to engage reliably for 40 hours/week.
• Clear written communication and constructive feedback.

Responsibilities

• Partner with AI researchers to define UI/UX principles and rubrics.
• Build polished, interactive web prototypes in code or with AI-native tools.
• Provide actionable feedback on layout, hierarchy, interactions, and polish.
• Explore varied visual styles and animation approaches for different products.
• Collaborate with designers and researchers to raise quality standards.

Skills

UI/UX design

Prototyping

React

Tailwind

HTML/CSS/JS

AI-native prototyping tools

Tools

Cursor

v0

Lovable

Bolt

Framer

Job description

Cincinnatus LLC is seeking a senior product designer with exceptional taste to shape how AI models design for the web and games. You’ll build high-quality prototypes and work closely with researchers to define great UI/UX patterns.

The role requires 7+ years of experience, strong prototyping skills in code or AI tools, and the ability to dedicate 40 hours per week. This is a full-time W-2 engagement with potential placement at a leading AI lab.