Senior Staff ML Infra Engineer, Ads Ranking

Reddit is a community-driven platform known for its open conversations and diverse interests. They are seeking a Senior Staff ML Infra Engineer to enhance their ML-powered ad ranking systems through improved infrastructure and automation. The role involves architecting ML training systems, driving system reliability, and mentoring engineers across teams.

Responsibilities:

• 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

Requirements:

• 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