Staff Machine Learning Engineer, Ads Content Understanding

About Reddit

Reddit is a community of communities, built on shared interests and authentic conversations. With millions of daily active visitors, it's a significant source of information and engagement. We are expanding our teams with top talent, offering a remote-friendly work environment across the United States.

About the Role

The Ads Content Understanding (ACU) team is central to Reddit's advertising business, developing signals that describe content, brand safety, and user intent. As a Staff Machine Learning Engineer, you will lead the ACU roadmap for the Monetization organization and serve as the technical owner for its ML systems. This role balances technical leadership, mentorship, and hands-on development of ML models and production systems.

Responsibilities:

• Provide technical leadership and mentorship to MLEs and SWEs working on ML within ACU, driving design reviews, setting technical standards, and enhancing team craft.
• Develop evaluation and quality monitoring systems for content understanding signals using SOTA LM-judge practices.
• Drive operational excellence for ACU's ML systems by defining SLOs, alerting, and dashboards for key signals.
• Build and evolve content understanding capabilities for commercial conversations (e.g., sentiment, product entities, intent) and operationalize them as robust signals.
• Lead the design and implementation of signals pipelines and produce an ACU signals registry, ensuring efficient serving at Reddit scale.
• Drive LLM and modern ML best practices within ACU, including defining when to prompt, finetune, or distill models, and leading distillation efforts to replace external APIs.
• Operate across the full ML lifecycle (problem framing, data, modeling, evaluation, deployment, monitoring, oncall), designing scalable MLOps pipelines and championing responsible AI.

Required Qualifications:

• 7+ years of relevant MLE experience delivering production ML systems (models + pipelines + serving) at scale, ideally in content understanding or Ads domains.
• Demonstrated Staff-level technical leadership: driving architecture decisions, standards, and design reviews across multiple teams, aligning PMs, DSs, and engineers.
• Excellent communication skills, with the ability to explain complex technical trade-offs to diverse audiences.
• Strong track record building and shipping NLP/language models/content understanding models to production with clear business outcomes.
• Practical experience using LLMs in production for labeling, evaluation, or distillation, managing quality, cost, and latency trade-offs.
• Deep experience with PyTorch, TensorFlow, or similar, and production-quality Python code (and ideally a statically typed language like Go/Java/C++).
• Experience designing ML systems and pipelines: offline training, feature pipelines, online serving, monitoring, and experimentation for high-traffic surfaces.

Benefits:

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

Pay Transparency: The base salary range for this position is $230,000 - $322,000 USD. This role may also be eligible for equity.