Research Engineer, Knowledge Foundations

Design and run experiments to improve AI information retrieval and reasoning.

• •The Knowledge Work team builds the training environments and evaluations that make Claude effective at real-world professional workflows.
• •As a Research Engineer on Knowledge, you'll design and run experiments that improve how Claude searches, retrieves, and reasons over information at scale.
• •Key Responsibilities Design, build, and iterate on training environments and data pipelines.
• •Run experiments end-to-end: form a hypothesis, build infrastructure, train models, analyze results.
• •Develop evaluations that meaningfully capture progress on search, retrieval, and reasoning quality.
• •Collaborate closely with researchers across RL Data, post-training, and product teams.
• •Own a clean, canonical set of evaluation tools and processes for Knowledge Work capabilities.
• •Requirements Highly experienced Python engineer who ships reliable, well-instrumented code.
• •Experience designing, running, and analyzing ML experiments.
• •Ability to work across the stack