[Remote] Principal Data Scientist, Ads

Note: The job is a remote job and is open to candidates in USA. Reddit is a community of communities and one of the internet’s largest sources of information. The Ads Data Science team is seeking a highly motivated Principal Data Scientist to drive the application of advanced quantitative methods across their advertising platform, focusing on optimizing the advertiser experience and collaborating with various teams to establish long-term measurement and prediction strategies. Responsibilities • Define the future of Ads Data Science: Own the design and long-term evolution of our core Ads Data Science solutions and infrastructure, building for the next several years of continued scale, revenue growth, and relevance. • Strategic leadership & scientific roadmap: Identify fundamental gaps and opportunities in our current systems (including platform, auction, targeting, and full-funnel relevance models). Lead the strategic design and scientific roadmap for new solutions to significantly improve Advertiser ROI, User experience, and Reddit revenue. • Drive end-to-end impact: Take end-to-end ownership of complex problem domains such as full funnel acceleration, advertiser lifetime value (LTV), and developing advanced predictive and causal frameworks that power Reddit’s strategic investments. • Establish scientific standards: Define and codify best practices for large-scale statistical modeling, economic analysis, causal inference, offline model evaluation, and A/B experimentation to ensure scientific rigor and trust across the Ads data science and engineering teams. • Technical deep dive & authority: Be the undisputed domain authority for data scientists, engineers, and product managers on complex problems involving large-scale behavioral data, foundational models for strategic insights, and the economics of marketplace dynamics. • Translate ambiguity into outcomes: Influence the design and definition of core business and performance metrics, robust measurement methodologies, and collaborate deeply with cross-org XFNs to align on strategic goals and translate insights into tangible action. • Influence and uplevel the organization: Lead technically minded peers and mentor senior data scientists, influencing technical and statistical direction across the entire product and engineering organization, and championing innovation in ad systems through advanced quantitative techniques. Skills • Demonstrated expertise in at least one of the following: ads marketplace understanding, auctioning/bidding, ads creative & format evaluation, measurement & experimentation at scale • Master's or Ph.D. in Economics, Statistics, Computer Science, Operations Research, or a related quantitative discipline • For M.S. holders: 12+ years of industry experience in applied science, data science, or machine learning engineering roles • For Ph.D. holders: 8+ years of relevant experience applied science, data science, or machine learning engineering roles • Advanced proficiency in statistical programming (Python or R) and SQL • Experience with statistical analysis, economic modeling, foundational machine learning and/or optimization techniques • Strong understanding of experimental design, causal inference, or A/B testing methodologies • Exceptional problem-solving and communication skills, with a track record of influencing product and engineering partners • Experience working in fast-paced, ambiguous environments with cross-functional teams • Proven experience in influencing large (500+ engineers/data scientists) organizations on technical direction, statistical rigor, and machine learning best practice Benefits • Comprehensive Healthcare Benefits and Income Replacement Programs • 401k Match • Family Planning Support • Gender-Affirming Care • Mental Health & Coaching Benefits • Flexible Vacation & Reddit Global Days off • Generous paid Parental Leave • Paid Volunteer time off Company Overview • Reddit is the heart of the internet, where millions of people get together to talk about any topic imaginable. It was founded in 2005, and is headquartered in San Francisco, California, USA, with a workforce of 1001-5000 employees. Its website is https://www.redditinc.com. Company H1B Sponsorship • Reddit, Inc. has a track record of offering H1B sponsorships, with 72 in 2025, 64 in 2024, 76 in 2023, 70 in 2022, 68 in 2021, 39 in 2020. Please note that this does not guarantee sponsorship for this specific role.