Staff / Principal

Reddit's Ads Data Science team is seeking a highly motivated Principal Data Scientist to drive the strategic application of advanced quantitative methods across our advertising platform. In this pivotal leadership role, you will define and implement the next generation of foundational data science solutions, leveraging expertise in statistics, econometrics, machine learning and/or other quantitative methods to optimize Reddit's Ads marketplace. You will partner closely with Analytics Engineering, and collaborate with Product, Engineering, and Business leaders to establish the 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 lifetime value (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, and mentor senior data scientists.

• Demonstrated expertise in at least one of: 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 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.
• 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. Benefits include comprehensive healthcare, 401k with employer match, flexible vacation, paid parental leave, and more.