Senior Data & Machine Learning Engineer

ABOUT THE ROLE Join an early-stage AI company building personalized advertising and recommendation technology. You will own the matching system end to end, from model development through real-time serving, helping shape a core product capability. WHAT YOU'LL DO - Build retrieval, ranking, and re-ranking systems to match ads with recipients. - Develop embedding and vector-search infrastructure for real-time ad selection. - Optimize ranking for click-through rate, advertiser return, publisher revenue, and subscriber relevance. - Own the feature store and serving path, including offline training, online inference, and consistency between them. - Apply large language models and foundation models to subscriber tagging, content understanding, and user modeling. - Take initiatives from prototype to production, including online learning, feedback systems, ETL/ELT pipelines, and warehouse transformations. - Create dashboards and scorecards to track system health and business and model performance. - Work with company leadership and engineering to set priorities, and help scale the recommendation system and future ML team. WHAT WE'RE LOOKING FOR - Five or more years of relevant experience, including at least three years building recommendation, ranking, or advertising systems. - Experience shipping production recommendation or matching systems across candidate generation, ranking, embedding-based retrieval, serving, and evaluation. - Background building ad ranking, click-through or conversion prediction, or ad-matching models. - Hands-on experience with embeddings and real-time vector search, such as FAISS, Milvus, Pinecone, pgvector, or similar tools. - Strong SQL skills and experience building data pipelines and transformation layers with dbt or similar tools, plus Postgres or analytical databases. - Ability to work independently in an early-stage environment; startup or team-building experience is beneficial. - Must be authorized to work in the United States without visa sponsorship. COMPENSATION & BENEFITS Base salary range: $200,000 to $300,000 annually. Visa sponsorship is not available. LOCATION Hybrid work arrangement. Candidates should be based in the New York City area, or in a U.S. time zone near Eastern time and able to travel to New York City quarterly.