Senior Data & Machine Learning Engineer

Join a small, early-stage AI team building a recommendation system for personalized advertising. You will own the matching stack end to end, from data and models through real-time serving, and help shape the system's technical priorities as it scales.

• 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 across click-through rate, advertiser return, publisher revenue, and subscriber relevance.

• Own the feature store, offline training, online inference, serving path, and pipeline health.

• 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 loops, ETL/ELT pipelines, and warehouse transformations.

• Create dashboards and automated scorecards to track performance and key metrics.

• Partner with company leadership and engineering to set priorities, with an opportunity to grow into leading an ML team.

Hybrid, with preference for candidates in the New York City area or in a nearby U.S. time zone who can travel to New York City quarterly.

• At least 3 years of experience with recommendation, ranking, or advertising systems, and 5 to 16 years of overall experience.

• Production experience owning recommendation or matching systems across candidate generation, ranking, embedding-based retrieval, serving, and evaluation.

• Experience building ad ranking, click-through or conversion prediction, or ad-matching models.

• Hands-on experience with embeddings and real-time vector search tools such as FAISS, Milvus, Pinecone, pgvector, or similar.

• Strong SQL skills and experience building data pipelines and transformation layers with dbt or similar tools, plus Postgres or columnar analytical databases.

• Early-stage startup or founder experience is valued; experience building an ML team and graduate study in computer science or machine learning are also relevant.

Base salary: $200,000 to $300,000 annually. Visa sponsorship is not available.