Research Engineer (Machine Learning, Reinforcement Learning)

• Our Reinforcement Learning teams lead Anthropic’s reinforcement learning research and development, playing a critical role in advancing our AI systems. We’ve contributed to all Claude models, with significant impacts on the autonomy and coding capabilities of Claude Sonnet 4.5 and Opus 4.5. Our work spans several key areas:
• Developing systems that enable models to use computers effectively
• Advancing code generation through reinforcement learning
• Pioneering fundamental RL research for large language models
• Building scalable RL infrastructure and training methodologies
• Enhancing model reasoning capabilities
• We collaborate closely with Anthropic’s alignment and frontier red teams to ensure our systems are both capable and safe
• We partner with the applied production training team to bring research innovations into deployed models, and are dedicated to implement our research at scale
• Our Reinforcement Learning teams sit at the intersection of cutting-edge research and engineering excellence, with a deep commitment to building high-quality, scalable systems that push the boundaries of what AI can accomplish
• As a Research Engineer within Reinforcement Learning, you will collaborate with a diverse group of researchers and engineers to advance the capabilities and safety of large language models
• This role blends research and engineering responsibilities, requiring you to both implement novel approaches and contribute to the research direction
• You’ll work on fundamental research in reinforcement learning, creating ‘agentic’ models via tool use for open-ended tasks such as computer use and autonomous software generation, improving reasoning abilities in areas such as mathematics, and developing prototypes for internal use, productivity, and evaluation
• Architect and optimize core reinforcement learning infrastructure, from clean training abstractions to distributed experiment management across GPU clusters. Help scale our systems to handle increasingly complex research workflows
• Design, implement, and test novel training environments, evaluations, and methodologies for reinforcement learning agents which push the state of the art for the next generation of models
• Drive performance improvements across our stack through profiling, optimization, and benchmarking. Implement efficient caching solutions and debug distributed systems to accelerate both training and evaluation workflows
• Collaborate across research and engineering teams to develop automated testing frameworks, design clean APIs, and build scalable infrastructure that accelerates AI research

Benefits

• Comprehensive health, dental, and vision insurance for you and your dependents

• Inclusive fertility benefits via Carrot Fertility

• 22 weeks of paid parental leave

• Flexible paid time off and absence policies

• Mental health support for you and your dependents

• Competitive salary and equity packages

• Optional equity donation matching at a 1:1 ratio, up to 25% of your equity grant

• Retirement plans with competitive matching

• Life and income protection plans

• $500/month flexible wellness and time saver stipend

• Commuter benefits

• Annual education stipend

• Home office stipends

• Relocation support for those moving for Anthropic

• Daily meals and snacks in the office

• Can balance research exploration with engineering implementation

• Care about code quality, testing, and performance

• Are proficient in Python and async/concurrent programming with frameworks like Trio

• Have industry experience in machine learning research

• Enjoy pair programming (we love to pair!)

• Are passionate about the potential impact of AI and are committed to developing safe and beneficial systems

• Have experience with machine learning frameworks (PyTorch, TensorFlow, JAX)

• Have strong systems design and communication skills

• Familiarity with LLM architectures and training methodologies

• Experience with reinforcement learning techniques and environments

• Experience with Kubernetes

• Experience with virtualization and sandboxed code execution environments

• Experience with distributed systems or high-performance computing

• Experience with Rust and/or C++

• Education requirements: We require at least a Bachelor’s degree in a related field or equivalent experience

• We encourage you to apply even if you do not believe you meet every single qualification. Not all strong candidates will meet every single qualification as listed

• Deadline to apply: None. Applications will be reviewed on a rolling basis