Senior Machine Learning Engineer, Ads Ranking

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.

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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. The year ahead is a busy one - join us!

We’re looking for a Senior 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.

• 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 behaviour.
• 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 MLEs and contribute to modelling best practices across the org.
• Shape the long‑term modelling vision across one or more domains (conversion, app ads, shopping, brand, etc.).

• 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: can 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 modelling quality through reviews and technical guidance.

• Comprehensive Healthcare Benefits and Income Replacement Programs
• 401k with Employer Match
• Global Benefit programs that fit your lifestyle, from workspace to professional development to caregiving support
• Family Planning Support
• Gender‑Affirming Care
• Mental Health & Coaching Benefits
• Flexible Vacation & Paid Volunteer Time Off
• Generous Paid Parental Leave

#LI-REMOTE

This job posting may span more than one career level.

In addition to base salary, this job is eligible to receive equity in the form of restricted stock units, and depending on the position offered, it may also be eligible to receive a commission. Additionally, Reddit offers a wide range of benefits to U.S.

-based employees, including medical, dental, and vision insurance, 401(k) program with employer match, generous time off for vacation, and parental leave. To learn more, please visit

To provide greater transparency to candidates, we share base pay ranges for all US-based job postings regardless of state. We set standard base pay ranges for all roles based on function, level, and country location, benchmarked against similar stage growth companies. Final offer amounts are determined by multiple factors including, skills, depth of work experience and relevant licenses/credentials, and may vary from the amounts listed below.

The base pay range for this position is: $266,000 — $372,400 USD.

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