Staff+ Software Engineer, Backend

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 Role: Anthropic is looking for experienced, product-minded engineers to own the backend systems that power user experiences across our API, Claude Code, and Claude.ai. You'll independently scope complex, multi-month projects through ambiguous problem spaces and lead peers through technical and product decisions; you'll drive alignment with product, peer engineering teams, and research to identify capability gaps and translate frontier model improvements into shipped products. You'll make architectural decisions that affect the reliability and scalability of systems serving hundreds of thousands of global users (including internal teams), and design processes that help your team operate effectively and never fail the same way twice - all while staying hands-on with the code and our models. We have multiple teams that are currently hiring. Team placement occurs after the interview process, taking into account your interests and experience alongside organizational needs. This flexible approach allows us to match talented engineers with the backend product efforts where they'll have the greatest impact and growth potential: 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 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. 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. 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. Passport: We're building the identity and verification product layer that enables safe model launches as Claude's capabilities expand. This critical effort partners with Safeguards, Auth & Identity, Policy, and Product

Own backend systems powering user experiences across the API, Claude Code, and Claude.ai. Independently scope multi-month projects in ambiguous problem spaces and lead peers through technical and product decisions; drive alignment with product, peer engineering teams, and research to identify capability gaps and translate frontier model improvements into shipped products. Make architectural decisions affecting reliability and scalability of systems serving hundreds of thousands of global users, and design processes that prevent repeated failures—all while staying hands-on with code and models. Contribute across multiple teams (API Core, API Capabilities, API Knowledge, Developer Experience, API Agents, API Distributability, Enterprise Foundations, Passport) to build, scale, and deploy Claude’s backend capabilities. Collaborate with inference, safeguards, research, and security/compliance functions to productionize next ideas, improve performance, ensure security, and deliver enterprise-ready features.