Staff Machine Learning Engineer, App Ads Modeling

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Reddit has a flexible first workforce!

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.

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. This position will sit on the App Ads Modeling team and report directly into the Ranking Org.

Responsibilities:

• 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.)

Required Qualifications:

• 7+ years of industry experience, including several years in applied ML roles

• Strong experience with Deep Learning architectures and ML frameworks (TensorFlow, PyTorch)

• Strong background in recommendation systems, ads ranking, or similar domains

• Experience working with large-scale datasets and complex feature pipelines

• Strong problem-solving and experimentation skills

• State of the Art models for Ads or Recsys experience (ex: Transformers, Recsys)

• Knowledge about Recsys or Ads funnel

• Track record of delivering high-impact models in production settings

• Comfort collaborating with infra and data teams on feature serving and training pipelines

Preferred Qualifications:

• Experience with conversion modeling, app ads, or performance/brand ads