Senior ML Infra 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 ML Infra 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 GPU-first training & serving, streaming/feature infra, and reliability/automation.

• Architect and significantly influence ML training/serving systems and tooling that unlock faster iteration and larger models.
• Drive adoption and reliability of ML systems and own a portfolio of initiatives across multiple teams.
• Improve efficiency: GPU utilization, training runtime, data loading, feature performance, and serving latency.
• Write high‑quality design docs; run design reviews; set standards for correctness, reliability, and velocity.
• Partner cross‑org on shared infra sequencing, requirements, and adoption.
• Mentor other engineers and contribute to engineering best practices across the org.

• 9+ years industry experience in Software / ML Infra Engineering.
• Strong systems background: distributed systems, data pipelines, service design, performance tuning, and operational excellence.
• Demonstrated experience improving ML training/serving reliability at scale.
• Can reason deeply about infra tradeoffs that affect modeling velocity and product outcomes.
• Ability to lead through influence: drive adoption across teams and build durable interfaces/standards.
• Demonstrated impact: leading cross‑team technical initiatives and influencing technical direction.
• Excellent communication: can explain tradeoffs clearly to both technical and non‑technical stakeholders.
• Comfortable mentoring other engineers and raising engineering 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

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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, visit

To provide greater transparency to candidates, we share base pay ranges for all U.S.

-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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