Senior Staff Machine Learning Engineer, ML Understanding

This is a fully remote position, open to applicants in United States.

📋 Description

• Develop a User Understanding Strategy: Establish a cohesive framework and strategy for user understanding, detailing representation methods (embeddings, tags, attributes, LLM-based user profiles), as well as their computation, storage, and exposure. Provide strategic leadership in user understanding and modeling, setting a long-term technical vision and enhancing the field's advancements.

• Create Foundational User Models: Oversee the design and execution of sophisticated user models, such as large-scale user representation learning (sequence-based, multi-interest, multi-task), sharing representations across various surfaces to enhance the personalization experience in key Reddit products like Feeds, Notifications, Search, and Ads, while balancing latency, cost, and performance.

• Innovate User Understanding with LLM/Gen-AI: Transform user modeling by utilizing LLMs to create a deeper understanding of users (e.g., dynamic user profiles, intent inference, semantic reasoning regarding user behavior). Investigate how LLMs can enhance or unify embeddings, attributes, and taxonomies for more adaptive, interpretable, and context-aware personalization.

• Implement Large Scale User Understanding as a System: Collaborate with platform teams to design and construct essential components for large-scale learning and serving, including storage/retrieval for embeddings, feature pipelines, and APIs. Work with ML/Ranking infrastructure to ensure low-latency serving, high availability, and integration with MLOps systems.

• Facilitate Cross-Team Integration & Impact: Collaborate with Feeds, Notifications, Search, and Ads teams to encourage experimentation and the adoption of new user understanding models with product teams across Reddit, ensuring measurable end-to-end impact on key metrics.

• Elevate Technical Standards & Mentor: Mentor senior to staff engineers, lead design reviews, guide technical decisions within the user understanding domain, and champion engineering processes and best practices.

⛳️ Requirements

• You possess a minimum of 10 years of experience in building and scaling production-grade ML systems, specifically in user modeling, large-scale representation learning, or recommender systems.

• You have a proven history of steering ambiguous, high-impact initiatives from concept to production, influencing both technical direction and execution.

• You are focused on product impact: you care about how your work affects real metrics (e.g., engagement, retention, revenue), not merely model quality.

• You have strong fundamentals in mainstream user understanding ML methodologies (e.g., representation learning, behavioral modeling, user clustering) and comprehend their trade-offs in real-world applications.

• You are enthusiastic about the GenAI transition and possess experience (or a strong intuition) in applying LLMs or foundation models to enhance existing systems, aiming for more than just incremental improvements.

• You think in systems rather than merely models: you consider data, training, evaluation, serving, and adoption as an integrated whole, designing with end-to-end impact in mind.

• You influence beyond your immediate team: you effectively partner with product, infrastructure, and other ML teams, driving alignment across multiple stakeholders.

• You elevate the technical standards: mentoring senior engineers, leading design reviews, and establishing best practices for constructing reliable, scalable ML systems.

• You are adept at navigating trade-offs between quality, latency, cost, and safety, particularly in large-scale, user-facing systems.

🏝️ Benefits

• 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