Senior Staff Machine Learning Engineer, Ads Ranking

Details

Reddit is a community of communities. It’s built on shared interests, passion, and trust, and is home to the most open and authentic conversations on the internet. Every day, Reddit users submit, vote, and comment on the topics they care most about. With 100,000+ active communities and approximately 116 million daily active unique visitors, Reddit is one of the internet’s largest sources of information.

We’re evolving and continuing our mission to bring community, belonging, and empowerment to everyone in the world. Providing a delightful and relevant experience to our users applies to our Ads like all of our offerings, and we’re excited to build a product that is best-in-class for our users and advertisers.

This role is part of Reddit’s Ads Ranking Org and focuses on enhancing ML-powered ad ranking systems through improved model architectures, contextual embeddings, and conversion-optimized modeling.

Responsibilities

• Design and train advanced ML models (e.g., DNNs, transformers) to power Reddit Ads Ranking models.
• Develop and optimize features including embeddings, contextual signals, and cross-session behavior.
• Own experimentation strategy: offline metrics, A/B design, readouts, and “next iteration” planning.
• Work closely with product, infra, and data teams to drive end-to-end model deployment and performance analysis.
• Mentor other machine learning engineers 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.).

Requirements

• 9+ years industry experience in ML Engineering / Applied ML.
• Demonstrated impact leading cross-team technical initiatives and influencing technical direction.
• Strong fundamentals in ML systems end-to-end.
• Excellent communication skills: able to explain tradeoffs clearly to both technical and non-technical stakeholders.
• Proven track record shipping DNN-based ranking/recs/ML models to production with measurable impact.
• Strong understanding of loss/labeling, sampling, calibration, bias/variance, train/serve skew, and online experimentation.
• Comfortable mentoring other engineers and raising modeling quality through reviews and technical guidance.

Benefits

• Comprehensive Healthcare Benefits and Income Replacement Programs
• 401k with Employer Match
• Global benefit programs for workspace, professional development, and caregiving support
• Family Planning Support
• Gender-Affirming Care
• Mental Health & Coaching Benefits
• Flexible Vacation & Paid Volunteer Time Off
• Generous Paid Parental Leave

Pay Transparency

Base pay range for this U.S.-based position: $266,000 - $372,400 USD. This role may also be eligible for equity (RSUs) and, depending on role, commission. Final offer is determined by factors including skills and experience.

Additional Information

• Location: Remote - United States. #LI-REMOTE
• In select roles/locations, interviews may be recorded, transcribed and summarized by AI; candidates may opt out prior to scheduled interviews.
• Candidate privacy and data handling practices are described in Reddit's Candidate Privacy Policy.
• Reddit is an equal opportunity employer and provides reasonable accommodations for applicants with disabilities.