Senior Machine Learning Engineer, Agentic Context Retrieval and Search (Nova)

Required

• 5+ years of hands-on MLE experience putting complex models into production at scale, including search, information retrieval, or recommendation systems.
• Master's or PhD in Computer Science, Machine Learning, AI, or a related field.
• You keep up with the latest research and focus on applying it: shipping reliable changes that measurably improve the product experience for customers.
• Deep IR expertise: lexical (BM25), dense (embeddings, ANN indexes), and hybrid retrieval, plus learning-to-rank.
• Production experience with search engines such as Elasticsearch, OpenSearch, or Vespa, including relevance tuning and reranking.
• Hands-on experience with RAG, query rewriting, reranking, and grounding techniques that reduce hallucination.
• Experience building agents on top of retrieval, such as multi-hop search or sufficiency checks.
• Strong evaluation practice: offline benchmarks, regression detection, A/B testing, and labeling pipelines.