Software Engineer, Backend

Anthropic•Seattle, WA

3d•Hybrid

About The Position

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 Role: Anthropic is looking for backend software engineers to work across our product engineering organization. You'll build the products and systems that bring Claude's capabilities to users and developers - from the APIs that hundreds of thousands of developers build on, to the enterprise features that let Fortune 500 companies deploy Claude at scale, to the agentic tools that are redefining how developers write code. This is a high-impact role where you'll work at the intersection of complex distributed systems and user-facing product development. You'll partner closely with frontend engineers, researchers, designers, and product managers to translate product vision into robust, scalable backend systems. There's no shortage of hard problems to solve. This role is part of our engineering pipeline hiring process. Rather than hiring for a single team, we're looking for exceptional engineers who will be matched to the team where they can have the greatest impact. During the application process, you'll have the opportunity to indicate which teams interest you most, and we'll work with you to find the best fit. API Core: You'll build and scale the foundation of the Claude API—the systems that deliver Claude's intelligence to every developer, from startups to enterprise. You'll own the performance, reliability, and efficiency of our core serving path, ensuring users get the most speed and value from our models. You'll partner closely with inference and safeguards to optimize the full stack. API Capabilities: You'll bring frontier model capabilities to developers through the Claude API, owning core features like vision, tool use, and computer use. You'll launch new models and ship the primitives that make Claude more capable with every release. You'll partner directly with research and inference to productionize what's next. API Distributability: The Claude API today is a rapidly growing platform serving developers and enterprises at scale—but reaching the next tier of enterprise customers requires transforming how and where we deploy it. The Distributability team owns that transformation: making the Claude API a cloud-native, managed product that runs wherever our customers need it, cross-cloud and on Anthropic's own infrastructure, with the enterprise-grade security, compliance, and operational capabilities to support it. API Knowledge: You'll focus on transforming Claude into a true knowledge worker by ensuring the model has access to and understanding of the right knowledge at the right time. You'll work on making it possible for developers to securely give Claude access to their data while automatically processing and retrieving relevant information. You'll partner directly with research to bring state-of-the-art retrieval advancements to developers. Developer Experience: You’ll focus on building products and tools to enable developers to harness the full power of LLMs to create successful, reliable, and groundbreaking applications with ease. You’ll build the tools to accelerate developers from idea to deployment. You'll help figure out how to leverage Claude to improve developer's usage of the API, such as generating and evaluating prompts while collaborating closely with the teams above to bring Claude's current and future capabilities to developers. API Agents: You'll focus on building the infrastructure and APIs that enable developers to create powerful agentic applications within the Claude API. You'll help developers with agent orchestration through capabilities like tool use, multi-step reasoning, and long-running task execution that allow Claude to take actions and accomplish complex goals on behalf of users. You'll partner with research to bring cutting-edge agent capabilities to production. Enterprise Foundations: We're looking for a software engineer to join our Enterprise Foundations team—the team that makes Claude enterprise-ready at scale. When a Fortune 500 company wants to roll out Claude to 100,000 employees, we're the team that makes it possible. You'll build the foundational systems that large organizations require before they can deploy AI at scale: user and permissions management, security and compliance features, and analytics infrastructure. This work directly converts product-market fit into revenue by removing the deployment blockers that prevent large organizations from adopting Claude broadly.

Requirements

Have 5+ years of relevant industry experience as a backend or product engineer, ideally leading projects of multi-month, complex scale
Are proficient in Python, Go, or similar backend languages and have experience with modern cloud infrastructure
Have strong demonstrated product sense - you think about the user experience even when writing server-side code
Take full ownership of your work, from design through deployment and operations
Can navigate ambiguity and make sound technical decisions independently, and have ideally operated in 0 to 1 and more mature team or company settings
Communicate effectively across functions and can translate between product requirements and technical implementation
Care deeply about code quality, testing, and operational excellence, and about the societal impact of the systems you build

Nice To Haves

Experience building or maintaining billing, payments, or financial infrastructure where data consistency and correctness are critical
Familiarity with containerization, sandboxed execution environments, or security-focused infrastructure design
Experience with identity and access management systems (authentication, authorization, SSO, RBAC)
Exposure to ML/AI systems or an understanding of how LLM inference and model serving pipelines work
Experience building internal developer tools, CI/CD systems, or platform capabilities that improved engineering velocity across an organization
Experience with multi-cloud or cloud-agnostic infrastructure patterns
Experience with REST APIs and service-oriented architectures at scale
Familiarity with modern frontend frameworks like React (our platform engineers sometimes work across the stack)