Principal Data Scientist, Ads

Reddit is a community of communities, built on shared interests, passion, and trust, with 100,000+ active communities and approximately 130 million daily active unique visitors. It is one of the internet’s largest sources of information.

Reddit's Ads Data Science team is seeking a highly motivated Principal Data Scientist to drive the strategic application of advanced quantitative methods across the advertising platform. This leadership role will define and implement next-generation data science solutions, leveraging statistics, econometrics, machine learning, and other quantitative methods to optimize Reddit's Ads marketplace. The role partners with Analytics Engineering, Product, Engineering, and Business leaders to establish long-term vision for measurement, prediction, and optimization.

• Own the design and long-term evolution of core Ads Data Science solutions and infrastructure.
• Lead strategic design and scientific roadmap for new solutions to improve Advertiser ROI, User experience, and Reddit revenue.
• Take end-to-end ownership of complex problem domains such as full funnel acceleration, advertiser LTV, and advanced predictive and causal frameworks.
• Define and codify best practices for large-scale statistical modeling, economic analysis, causal inference, offline model evaluation, and A/B experimentation.
• Be the domain authority for data scientists, engineers, and product managers on complex problems involving large-scale behavioral data and marketplace dynamics.
• Influence core business and performance metrics, measurement methodologies, and cross-org alignment.
• Mentor senior data scientists and influence technical and statistical direction across the organization.

• Demonstrated expertise in ads marketplace, auctioning/bidding, ads creative & format evaluation, or measurement & experimentation at scale.
• Master's or Ph.D. in Economics, Statistics, Computer Science, Operations Research, or related quantitative discipline.
• For M.S. holders: 12+ years of industry experience in applied science, data science, or machine learning engineering. For Ph.D. holders: 8+ years of relevant experience.
• 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.
• Proven experience influencing large (500+ engineers/data scientists) organizations on technical direction and statistical rigor.

Base salary range: $268,000—$365,100 USD. Eligible for equity in the form of restricted stock units, and possibly commission.

Comprehensive healthcare benefits, 401k with employer match, flexible vacation & paid volunteer time off, generous paid parental leave, mental health & coaching benefits, family planning support, gender-affirming care, and global benefit programs.

Apply via the Greenhouse job posting.