Principal Data Scientist, Ads

Details

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 to advance the intelligence powering the advertiser experience on Reddit. In this leadership role you will define and implement the next generation of foundational data science solutions, leveraging statistics, econometrics, machine learning, and other quantitative methods to optimize Reddit's Ads marketplace. You will partner closely with Analytics Engineering, Product, Engineering, and business leaders to establish long-term vision for measurement, prediction, and optimization, and mentor the broader team to champion scientific rigor and causal inference.

Responsibilities

• Define the future of Ads Data Science: own the design and long-term evolution of core Ads Data Science solutions and infrastructure for scale and revenue growth.
• Strategic leadership & scientific roadmap: identify gaps and opportunities across platform, auction, targeting, and full-funnel relevance models; lead design of new solutions to improve Advertiser ROI, user experience, and revenue.
• Drive end-to-end impact: take ownership of complex domains such as full-funnel acceleration, advertiser lifetime value (LTV), and develop predictive and causal frameworks powering strategic investments.
• Establish scientific standards: define best practices for large-scale statistical modeling, economic analysis, causal inference, offline model evaluation, and A/B experimentation.
• Technical authority: act as domain authority for data scientists, engineers, and PMs on problems with large-scale behavioral data, foundational models, and marketplace economics.
• Translate ambiguity into outcomes: influence definition of core business/performance metrics, measurement methodologies, and collaborate with cross-functional teams to translate insights into action.
• Influence and uplevel the organization: lead and mentor senior data scientists and influence technical/statistical direction across product and engineering.

Requirements

• 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 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 in 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, and 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 influencing large (500+ engineers/data scientists) organizations on technical direction, statistical rigor, and machine learning best practices.

Benefits

• Comprehensive healthcare benefits and income replacement programs
• 401(k) match
• Family planning support and gender-affirming care
• Mental health & coaching benefits
• Flexible vacation & Reddit Global Days off
• Generous paid parental leave
• Paid volunteer time off

Pay Transparency

• Base pay range for this position (US): $26,800 - $365,100 USD.
• Eligible for equity (RSUs) and potentially commission depending on role. Final offers determined by skills, experience, and other factors.

Additional Notes

• In select roles/locations interviews may be recorded, transcribed, and summarized by AI; candidates may opt out prior to scheduled interviews.
• Reddit is an equal opportunity employer and will provide reasonable accommodations for qualified individuals with disabilities.