Staff Machine Learning Engineer (App Ads Modeling)

• We’re looking for a Staff-level Machine Learning Engineer to join Reddit’s Ads Ranking Org. This role is part of a broader effort to enhance Reddit’s ML-powered ad ranking systems through improved model architectures, contextual embeddings, and conversion-optimized modeling
• This position will sit on the App Ads Modeling team and report directly into the Ranking Org
• Design and train advanced ML models (e.g., DNNs, transformers) to power Reddit Ads Ranking
• Develop and optimize features including embeddings, contextual signals, and cross-session behavior
• Work closely with product, infra, and data teams to drive end-to-end model deployment and performance analysis
• Mentor other MLEs and contribute to modeling best practices across the org
• Shape the long-term modeling vision across one or more domains (conversion, app ads, shopping, brand, etc.)

Benefits

• Comprehensive health benefits
• Flexible vacation & Reddit global days off
• Family planning funds & 4+ months paid parental leave
• Personal & professional development funds
• Paid volunteer time off
• Workspace & home office benefits- The ideal candidate will bring strong end-to-end modeling expertise, a deep understanding of modern deep learning techniques, and a passion for building systems that drive measurable impact in ads marketplaces
• While ads experience is a plus, strong modelers from recommendation systems, search relevance, or other performance-driven domains are encouraged to apply
• Knowledge about Recsys or Ads funnel
• 7+ years of industry experience, including several years in applied ML roles
• Strong experience with Deep Learning architectures and ML frameworks (TensorFlow, PyTorch)
• State of the Art models for Ads or Recsys experience (ex: Transformers, Recsys)
• Experience working with large-scale datasets and complex feature pipelines
• Comfort collaborating with infra and data teams on feature serving and training pipelines
• Strong background in recommendation systems, ads ranking, or similar domains
• Track record of delivering high-impact models in production settings
• Strong problem-solving and experimentation skills
• Experience in ads marketplaces at peer companies
• Publications, patents, or industry contributions in applied ML or ranking systems
• Experience with conversion modeling, app ads, or performance/brand ads