Senior Staff Machine Learning Engineer, Ads Ranking

Reddit is a community of communities, built on shared interests, passion, and trust. It hosts 100,000+ active communities and approximately 130 million daily active unique visitors, making it one of the internet's largest sources of information.

We are seeking a Senior Staff Machine Learning Engineer to define and accelerate how we leverage agentic AI to transform machine learning models and modeling workflows. This high-impact role focuses directly on modeling leverage—enhancing model quality and velocity—rather than building general infrastructure. As a senior staff engineer, you will operate as a technical leader across the entire modeling loop, utilizing modern AI-assisted development systems (such as Claude, Cursor, and comparable tools) to make model development faster, more rigorous, and significantly more effective across the organization.

• Develop advanced ML models and the agentic workflows that help teams design, train, evaluate, and improve them.
• Use tools such as Claude, Cursor, and comparable AI-assisted development systems to investigate model behavior, generate and test hypotheses, automate repetitive analysis, and improve code and experiments.
• Build reliable loops for data and label analysis, feature and embedding development, architecture comparison, hyperparameter optimization, error analysis, and experiment readouts.
• Design evaluation harnesses that measure both model outcomes and agent/workflow quality, including correctness, reproducibility, regressions, cost, and latency.
• Partner with product, data science, ML infrastructure, and engineering teams to connect modeling improvements to user and business outcomes.
• Set technical direction across teams, mentor engineers, and raise the bar for modeling rigor and AI-assisted engineering.

• 9+ years of experience in ML engineering, applied ML, or a related field, with substantial production impact.
• Senior Staff-level technical leadership and a record of influencing direction across teams.
• Deep modeling expertise and strong fundamentals in data, objectives, architectures, optimization, evaluation, and experimentation.
• Concrete examples of using agentic AI or AI coding tools to produce better ML outcomes—not just faster code generation.
• Ability to design guardrails and evaluations that make autonomous or semi-autonomous workflows trustworthy.
• Strong coding ability in Python and fluency with modern ML frameworks and data tooling.
• Clear, concise communication and a collaborative, low-ego approach to technical leadership.

• 100% remote opportunity (4 office locations for hybrid/onsite work preference in NY, SF, LA and Chicago)
• Competitive salary and equity options
• Comprehensive health benefits (medical, dental, vision) & workplace perks (home office set up stipend etc)
• Generous 401k matching
• Flexible vacation policy
• Paid parental leave (4+ months)
• Family planning support
• Paid volunteer time off

The base salary range for this position is $292,500—$409,500 USD. 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. 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.