Senior Data Scientist, Ads Fraud & Safety — Remote US

Reddit, Inc.; Northern (KY); Hybrid; USD 191,000 - 267,000; Full time

Benefits offered by this job

Healthcare Benefits and Income Repl.

401k with Employer Match

Global Benefit programs

Family Planning Support

Mental Health & Coaching Benefits

Job summary

Reddit, Inc. is seeking a Senior Data Scientist to lead ads fraud detection within Safety. You will partner with Ads Product, ML, Engineering, and Policy to identify fraud patterns and build scalable detection and enforcement pipelines.

This role offers high impact ownership in a greenfield space, with opportunities to shape strategy, drive cross-functional roadmaps, and mentor other data scientists while advancing ads integrity across the platform.

Qualifications

• Ph.D. or MS with industry data science experience.
• Production detection pipelines experience.
• Strong fraud/abuse detection methods knowledge.
• Experience partnering with Product and Engineering.
• Experience applying AI/LLMs to workflows.

Responsibilities

• Lead the ads fraud detection strategy by defining taxonomies, labels, sampling plans, metrics and evaluation frameworks.
• Analyze large, complex datasets to uncover fraud patterns and translate findings into detection requirements.
• Design scalable ads fraud detection and enforcement pipelines with Engineering and ML teams.
• Own the full detection lifecycle: backtesting, thresholds, offline/online evaluation, deployment and retirement.
• Build and maintain ML and GenAI-enabled models to improve detection and enforcement quality.
• Balance fraud loss, advertiser risk, customer experience, and business goals when setting thresholds.
• Partner with Ads and Safety to shape strategy, data foundations, and governance.
• Translate analyses into clear narratives for senior stakeholders and mentor other data scientists.

Skills

Fraud detection

Python

SQL

Statistics

LLMs in DS

Communication

Education

PhD in Statistics/CS/Applied Math

MS with 4+ years data science

Tools

ML frameworks

SQL tooling

Job description

Reddit, Inc. is seeking a Senior Data Scientist to lead ads fraud detection within Safety. You will partner with Ads Product, ML, Engineering, and Policy to identify fraud patterns and build scalable detection and enforcement pipelines.

This role offers high impact ownership in a greenfield space, with opportunities to shape strategy, drive cross-functional roadmaps, and mentor other data scientists while advancing ads integrity across the platform.