Staff Machine Learning Engineer, Ads Ranking

We’re looking for a Staff 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 allows the opportunity to contribute across key modeling focus areas such as conversion, app ads, shopping, brand ads, or core ranking.

What you bring:

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

Day-to-Day 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.)

Most Challenging Aspects:

• Balancing generalization and specificity in modeling across different ad formats
• Managing trade-offs between model complexity, latency, and prediction quality
• Navigating cross-functional alignment to scale high-impact ML initiatives

What Differentiates This Role:

• Direct path to measurable product and revenue impact
• Opportunity to shape foundational ML modeling across Reddit Ads
• Flexible scope based on modeling strengths (conversion, app ads, core ranking, etc.)
• Exposure to diverse ad surfaces (feed, video, shopping, brand) and cutting-edge ML techniques

What We Offer:

• A dynamic, supportive work environment with a diverse team of engineers and cross-functional partners
• Opportunities for professional growth and development, with a focus on continuous learning and skill-building
• A competitive salary and benefits package, with a focus on work-life balance and employee well-being
• Flexible work arrangements, including remote work options, to support your individual needs and preferences
• The chance to work on high-impact projects that drive real results for our users and advertisers

Benefits:

• Comprehensive Healthcare Benefits and Income Replacement Programs
• 401k Match
• Family Planning Support
• Gender-Affirming Care
• Mental Health & Coaching Benefits
• Flexible Vacation & Reddit Global Days Off
• Generous paid Parental Leave 
• Paid Volunteer time off

#LI-Remote

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Reddit is proud to be an equal opportunity employer, and is committed to building a workforce representative of the diverse communities we serve.  Reddit is committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. If, due to a disability, you need an accommodation during the interview process, please let your recruiter know.