Principal UX Engineer - Ads Design & AI Tools

The Ads Design & Research team shapes the end-to-end advertising experience across Reddit—spanning advertiser platforms, consumer ad experiences, performance measurement, and underlying platform systems. As a Principal UX Engineer, you will treat code as a core product-design medium: building functional prototypes, connecting early concepts to production data streams, and accelerating the transition from design intent to engineering execution. Operating at the strategic intersection of design, frontend engineering, and AI-assisted workflows, you will set the technical strategy for UX Engineering across Reddit Ads, build reusable frontend tools, and raise the bar for interaction fidelity, performance, and accessibility across multi-sided ad platforms.

Key Responsibilities

• UX Engineering Strategy: Define, lead, and execute the overarching UX Engineering vision across multiple product verticals within Reddit Ads.
• Production-Adjacent Prototyping: Build high-fidelity functional prototypes, workflow tools, interactive components, and PR-ready codebases using React and TypeScript to test assumptions and validate complex user flows.
• AI-Native Tooling & Workflows: Architect AI-assisted workflows, custom developer/designer agents, skills, and interactive tools that revolutionize how the Ads Design team explores, prototypes, and ships features.
• Strategic Cross-Functional Leadership: Partner with senior leads across Design, Research, Product Management, Engineering, and Data Science to shape product direction for complex, ambiguous opportunities.
• Systems & Platform Architecture: Create reusable design system patterns, UI component libraries, internal toolchains, and platform frameworks that streamline design-to-production pipelines for partner teams.
• Craft & Accessibility Standards: Establish standards for interaction design quality, performance optimization, web accessibility (WCAG), and frontend code architecture across ad experiences.
• Capability Growth & Mentorship: Mentor practitioners across engineering and design disciplines, fostering the growth of UX Engineering as a core capability across Reddit.

Requirements

UX Engineering, Frontend Systems & Craft Depth

• Experience Track: Significant experience operating at the intersection of product design and frontend software engineering, with a proven track record of shipping complex interactive software products.
• Modern Frontend Stack: Deep hands-on engineering expertise in React, TypeScript, and modern Web APIs.
• Systems & Infrastructure: Proven experience authoring production-adjacent prototypes, design systems, internal tools, or frontend libraries adopted by cross-functional teams.
• Multi-Sided System Acumen: Experience building complex digital products—such as advertising engines, two-sided marketplaces, enterprise software, analytics platforms, developer tools, or AI-driven workflows.
• AI Tooling & Prototyping: Practical fluency with AI-assisted coding paradigms, LLM agents, and modern rapid-prototyping environments.
• Systems Thinking & Portfolio: A portfolio or project archive demonstrating technical architecture, systems design, organizational complexity, and cross-functional execution alongside software engineering teams.
• Strategic Communication: Exceptional written, verbal, and visual communication skills to influence executive stakeholders and simplify ambiguous product spaces.

Total Rewards & Benefits

• Compensation & Equity: Annual base salary range ($245,800 – $344,100 USD) + equity grants in the form of Restricted Stock Units (RSUs) + potential bonus eligibility.
• Healthcare & Income Protection: Comprehensive medical, dental, and vision insurance with 100% employer-matched coverage options and global income protection plans.
• Family & Gender-Affirming Care: Comprehensive family planning support, gender-affirming care, paid parental leave, and caregiving stipends.
• Mental Health & Lifestyle: Dedicated mental health coaching, workspace stipends, professional development allowances, and flexible vacation + paid volunteer time off.
• Retirement Planning: 401(k) retirement program with competitive employer matching