Staff Software Engineer, Code RL

Code RL at Anthropic drives reinforcement learning efforts behind Claude's coding capabilities, creating and scaling agentic coding environments. This is an engineering role with unusual latitude to set technical direction and standards.

• Design widely-used APIs, frameworks, and abstractions that other engineers and researchers build on.
• Embed with research teams on a rotational basis, building systems and APIs and transferring ownership.
• Work directly in research codebases, improving reliability and structure.
• Anticipate silent failure modes and prevent them structurally through type safety, invariants, testing, and refactors.
• Contribute to reliability of production RL systems, including monitoring, regression detection, and triage tooling.
• Help define engineering standards, review practices, and design patterns.

• Deep expertise in Python, including static typing, safe async and concurrency patterns, and performant code.
• Track record of designing intuitive, safe APIs or frameworks.
• Experience working in large, evolving, or research-style codebases.
• Demonstrated ability to anticipate failure modes, especially silent ones.
• Strong written and verbal communication skills.
• Comfort with ambiguity.

• Experience building infrastructure, tooling, or frameworks for ML research or RL workflows.
• Familiarity with reinforcement learning concepts, agentic systems, or LLM training pipelines.
• Experience with large-scale distributed systems.
• Experience with client libraries or SDKs on sandboxed, containerized, or remote execution platforms.
• Experience with large-scale data processing or dataset lifecycle management.
• Experience designing plugin systems or extensible class hierarchies.
• Experience embedding with or consulting for other teams.
• Experience defining code standards, lint rules, or static verification approaches.
• Prior experience as a technical lead or maintaining an open source project.

Annual Salary: $405,000—$625,000 USD.

Anthropic offers competitive compensation and benefits, optional equity donation matching, generous vacation and parental leave, flexible working hours, and a lovely office space.

Apply via the provided link.