Principal Consumer Data Scientist - RecSys & AI

We are seeking a senior Principal Data Scientist to serve as a scientific thought leader, shaping how Reddit understands, models, and optimizes its consumer ecosystem and user flywheel. In this high-impact position, you will define the measurement, representation, experimentation, and modeling strategies for fundamental consumer challenges: how users discover value, build long-term engagement habits, interact within community ecosystems, and express intent. Operating across deep learning frameworks (PyTorch, JAX), causal inference, and recommendation systems, you will partner with Product, Engineering, and Research executives to convert complex consumer behaviors into durable, production-grade statistical systems.

Key Responsibilities

• Scientific Direction & Strategy: Set the overarching scientific roadmap for consumer growth, personalization, content relevance, recommender engines, intent modeling, and community health.
• Consumer Flywheel & Intent Modeling: Architect multi-dimensional models representing users, content nodes, subreddits, and their dynamic interactions over time to drive high-capacity personalization platforms.
• Ecosystem Health & Measurement: Establish measurement frameworks balancing competing objectives—distinguishing temporary short-term metric shifts from long-term user retention, lifetime value (LTV), and network health.
• Causal Inference & Experimentation: Lead advanced experimentation strategies to address complex feedback loops, selection bias, interference, network effects, and distribution shifts across heterogeneous user cohorts.
• Production Integration: Guide the deployment of representation learning systems, contextual models, and graph representations into live production environments.
• Executive Alignment & Mentorship: Translate complex algorithmic methodologies into clear strategic guidance for C-suite leaders while mentoring data science leads across the organization.

Requirements

Scientific Depth & Machine Learning Expertise

• Experience Track: Substantial hands-on experience applying data science, machine learning, statistics, or causal inference to complex consumer internet platforms.
• Core Domain Expertise: Deep expertise in one or more core domains: Recommender Systems (RecSys), Information Retrieval, Personalization, Knowledge Graphs, Representation Learning, User Lifecycle/LTV, or Causal Inference.
• Deep Learning Frameworks: Hands-on proficiency with advanced machine learning architectures (sequential/contextual modeling, deep neural networks) using PyTorch or JAX.
• Complex Ecosystem Systems: Advanced understanding of modeling two-sided feedback loops, network interference, content supply dynamics, and user selection effects.
• Cross-Functional Influence: Exceptional written and verbal communication skills with a proven ability to align cross-functional leaders in Product, Engineering, and Research.
• Ambiguity & Technical Judgment: Track record of framing ambiguous business problems into rigorous scientific hypotheses and scalable engineering roadmaps.

Total Rewards & Benefits

• Compensation & Equity: Annual base salary range ($313,000 – $365,100 USD) + competitive Restricted Stock Unit (RSU) equity package.
• Comprehensive Healthcare: Fully inclusive medical, dental, and vision insurance options for employees and dependents.
• Family & Lifestyle Support: Paid parental leave, family planning programs, mental health coaching, and gender-affirming care.
• Retirement & Vacation: 401(k) program with employer match alongside flexible vacation policies and paid volunteer time off.