Reddit is a community of communities. It’s built on shared interests, passion, and trust, and is home to the most open and authentic conversations on the internet. Every day, Reddit users submit, vote, and comment on the topics they care most about. With 100,000+ active communities and approximately 130 million daily active unique visitors, Reddit is one of the internet’s largest sources of information. For more information, visit www.redditinc.com. Reddit’s Ads Design & Research team shapes the end-to-end advertising experience across advertiser tools, consumer ad experiences, measurement, and the systems that connect them. We’re looking for a Principal UX Engineer who sees code as a product-design medium: a way to make ideas tangible, connect prototypes to real systems and data, and help teams move from exploration to engineering-ready product direction faster. This is a strategic, hands-on role at the intersection of design and engineering. You’ll work across Reddit Ads to shape product direction, build production-adjacent prototypes and tools, and help establish UX Engineering as a capability for the Ads Design team. You’ll partner closely with Design, Research, Product, Engineering, and Data Science while staying deeply involved in the craft. WHAT YOU’LL DO * Define and lead the UX Engineering strategy across multiple areas of Reddit Ads. * Build high-quality functional prototypes, workflow tools, agents, and PR-ready product experiences that help teams explore ideas, test assumptions, and move faster from design intent to engineering review. * Partner with senior cross-functional leaders to shape product direction and bring clarity to complex, ambiguous opportunities. * Create reusable tools, systems, components, and workflows that make it easier to move from design and research into production. * Raise the bar for interaction quality, accessibility, performance, and technical craft across the Ads experience. * Build AI-native workflows, skills, agents, and tools that improve how Ads Design explores, prototypes, collaborates, and ships. * Mentor other practitioners and help grow UX Engineering as a capability across Reddit. WHAT WE’RE LOOKING FOR * Deep experience at the intersection of product design and engineering, with a track record of building sophisticated interactive products. * Strong hands-on expertise with modern frontend technologies such as React and TypeScript. * Experience building production-adjacent prototypes, internal tools, systems, or frontend infrastructure that other designers and engineers can use. * Excellent product and interaction judgment, with the ability to turn complex ideas into intuitive, high-quality experiences. * Experience working across multiple teams or product areas and influencing product direction beyond a single project. * Strong systems thinking, with experience creating reusable patterns, platforms, or tools that help other teams move faster. * Fluency with AI-assisted coding, agents, and advanced prototyping workflows. * The ability to navigate ambiguity, make thoughtful tradeoffs, and bring design, engineering, product, and research perspectives together. * Strong communication and collaboration skills, particularly with senior cross-functional partners. * A portfolio or body of work that shows use cases, technical architecture, systems thinking, organizational complexity, and collaboration with engineering teams, not only polished UI outcomes. * A passion for staying hands-on while helping others do their best work. Experience in advertising is helpful, but it isn’t required. We’re also interested in people who have worked on complex products such as marketplaces, enterprise tools, analytics, commerce, developer platforms, AI-powered experiences, or other multi-sided ecosystems. Benefits: * Comprehensive Healthcare Benefits and Income Replacement Programs * 401k with Employer Match * Global Benefit programs that fit your lifestyle, from workspace to professional development to caregiving support * Family Planning Support * Gender-Affirming Care * Mental Health & Coaching Benefits * Flexible Vacation & Paid Volunteer Time Off * Generous Paid Parental Leave  Pay Transparency: This job posting may span more than one career level. In addition to base salary, this job is eligible to receive equity in the form of restricted stock units, and depending on the position offered, it may also be eligible to receive a commission. Additionally, Reddit offers a wide range of benefits to U.S.-based employees, including medical, dental, and vision insurance, 401(k) program with employer match, generous time off for vacation, and parental leave. To learn more, please visit https://www.redditinc.com/careers/. To provide greater transparency to candidates, we share base salary ranges for all US-based job postings regardless of state. We set standard base pay ranges for all roles based on function, level, and country location, benchmarked against similar stage growth companies. Final offer amounts are determined by multiple factors including, skills, depth of work experience and relevant licenses/credentials, and may vary from the amounts listed below. The base salary range for this position is: $245,800—$344,100 USD In select roles and locations, the interviews will be recorded, transcribed and summarized by artificial intelligence (AI). You will have the opportunity to opt out of recording, transcription and summarization prior to any scheduled interviews. During the interview, we will collect the following categories of personal information: Identifiers, Professional and Employment-Related Information, Sensory Information (audio/video recording), and any other categories of personal information you choose to share with us. We will use this information to evaluate your application for employment or an independent contractor role, as applicable.  We will not sell your personal information or disclose it to any third party for their marketing purposes.  We will delete any recording of your interview promptly after making a hiring decision.  For more information about how we will handle your personal information, including our retention of it, please refer to our Candidate Privacy Policy for Potential Employees and Contractors. Reddit is proud to be an equal opportunity employer, and is committed to building a workforce representative of the diverse communities we serve.  Reddit is committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. If, due to a disability, you need an accommodation during the interview process, please let your recruiter know.