SEAN COOK

Lead the Data Science org powering Nextdoor's advertising platform. Built scalable systems in ranking, targeting, and performance ads while pioneering agentic DS workflows to accelerate experimentation velocity.

• Built and led the DS org behind Nextdoor's first-party ad server, driving continuous YoY revenue growth through marketplace optimization, click and conversion modeling, pacing improvements, and new ad format launches.
• Developed modeled audiences and targeting capabilities that improved advertiser ROI; expanded monetization surfaces through Search Ads and Leads business creation, generating tens of millions in incremental revenue.
• Introduced agentic Data Science tooling (Cursor, Claude, custom Python libraries) to accelerate ads experimentation, reducing time-to-insight for campaign analysis and model iteration.

Led 14 data scientists and managers building trust and enforcement systems across Meta's business and advertiser ecosystem, protecting billions of users while preserving legitimate business experiences.

• Built models that tiered businesses by trust level, then calibrated enforcement proportionally. Significantly reduced false actions on legitimate advertisers while mitigating billions in fraud and abuse.
• Created Meta's first automated business compromise detection and recovery system, using hierarchical traversal of invitation graphs to identify compromised root accounts and resolve thousands of cases simultaneously.
• Supported analytics for content integrity, political advertising compliance, and HEC (housing, employment, credit) ad fairness, ensuring enforcement met regulatory requirements across Meta's ad surfaces.

• Increased revenue through lead scoring, forecasting, and ROI models for marketing across 7 channels.
• Built data communities, managing events and speakers. Led content creation for SQL/Python blog.

• Integrated NPS into Intuit QuickBooks, leveraging UX feedback for product development.
• Drove initiatives combining data science and UI/UX, improving conversions, retention, and satisfaction.

• Managed data quality control for ad-tech DMP. Designed metrics and tools ensuring real-time database health.
• Created whitepapers, technical materials, and promotional content for marketing initiatives.

• Built financial models for retail site selection, generating millions in revenue through optimized real estate decisions.