Research Engineer, Machine Learning (Reinforcement Learning)

Anthropic; San Francisco (CA); Hybrid; USD 500,000 - 850,000; Full time

Benefits offered by this job

Equity donation matching

Generous vacation & parental leave

Flexible working hours

Office in SF

Job summary

Anthropic is seeking a Research Engineer in Reinforcement Learning to advance capabilities and safety of large language models. You will blend research and engineering, implement novel approaches, and contribute to research directions.

Expect to work on agentic models via tool use for open-ended tasks such as computer use and autonomous software generation. You will architect core RL infrastructure, design new training environments, and drive performance improvements across the stack.

Qualifications

• Bachelor’s degree in a field relevant to the role.
• Strong programming ability in Python with modern ML tooling.
• Experience delivering ML research in production or deployment contexts.
• Experience balancing exploratory research with engineering implementation.

Responsibilities

• Architect and optimize reinforcement learning infrastructure and experiment management across GPU clusters.
• Design and test training environments and evaluation methodologies for RL agents.
• Improve system performance via profiling, optimization, and distributed debugging.
• Collaborate across research and engineering to build scalable AI research infrastructure.

Skills

Python

Async/Concurrent

ML frameworks

Research–to–engineering

Pair programming

Code quality

System design

Communication

Education

Bachelor’s degree in a relevant field

Tools

Kubernetes

Virtualization

Sandboxed execution environments

Distributed systems

Rust/C++

Job description

About Anthropic

Anthropic’s mission is to create reliable, interpretable, and steerable AI systems. We want AI to be safe and beneficial for our users and for society as a whole. Our team is a quickly growing group of committed researchers, engineers, policy experts, and business leaders working together to build beneficial AI systems.

About Anthropic

Anthropic’s mission is to create reliable, interpretable, and steerable AI systems. We want AI to be safe and beneficial for our users and for society as a whole. Our team is a quickly growing group of committed researchers, engineers, policy experts, and business leaders working together to build beneficial AI systems.

About The Teams

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.

About The Role

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.

Representative Projects

• 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.

You May Be a Good Fit If You

• Are proficient in Python and async/concurrent programming with frameworks like Trio
• Have experience with machine learning frameworks (PyTorch, TensorFlow, JAX)
• Have industry experience in machine learning research
• Can balance research exploration with engineering implementation
• Enjoy pair programming (we love to pair!)
• Care about code quality, testing, and performance
• Have strong systems design and communication skills
• Are passionate about the potential impact of AI and are committed to developing safe and beneficial systems

Strong Candidates May Have

• Familiarity with LLM architectures and training methodologies
• Experience with reinforcement learning techniques and environments
• Experience with virtualization and sandboxed code execution environments
• Experience with Kubernetes
• Experience with distributed systems or high-performance computing
• Experience with Rust and/or C++

Strong Candidates Need Not Have

• Formal certifications or education credentials
• Academic research experience or publication history

Deadline to apply

None. Applications will be reviewed on a rolling basis.

Annual Salary

$500,000—$850,000 USD

Logistics

Minimum education: Bachelor’s degree or an equivalent combination of education, training, and/or experience

Required field of study: A field relevant to the role as demonstrated through coursework, training, or professional experience

Minimum years of experience: Years of experience required will correlate with the internal job level requirements for the position

Location-based hybrid policy: Currently, we expect all staff to be in one of our offices at least 25% of the time. However, some roles may require more time in our offices.

Visa sponsorship: We do sponsor visas! However, we aren't able to successfully sponsor visas for every role and every candidate. But if we make you an offer, we will make every reasonable effort to get you a visa, and we retain an immigration lawyer to help with this.

Guidance on Candidates' AI Usage

Learn about our policy for using AI in our application process.

Come work with us!

Anthropic is a public benefit corporation headquartered in San Francisco. We offer competitive compensation and benefits, optional equity donation matching, generous vacation and parental leave, flexible working hours, and a lovely office space in which to collaborate with colleagues.

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. Research shows that people who identify as being from underrepresented groups are more prone to experiencing imposter syndrome and doubting the strength of their candidacy, so we urge you not to exclude yourself prematurely and to submit an application if you're interested in this work. We think AI systems like the ones we're building have enormous social and ethical implications. We think this makes representation even more important, and we strive to include a range of diverse perspectives on our team.