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: Platform Intelligence: 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. Platform Ecosystem: The Ecosystem team is empowering the next big industries beyond coding to build on our platform & creating the right commercial rails to let any business in our ecosystem profit from building on Claude. As an early member of this foundational effort, you'd identify and build for the next 10x markets starting with Life Sciences and Healthcare. We also build the commercial rails and controls that let the platform do business anywhere, with anyone, and turn Claude from a cost line into a revenue line. We are hiring founding engineers for these two pillars. We are looking for engineers who have good product and business sense to drive strategy, dive into different stacks, and break through walls to drive these 0 -> 1 efforts. You'll be working closely with product, design, GTM, FDE, and other internal & external customers to build out and deliver on the strategy. Platform Serving: 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. Agentic Systems: You'll build the infrastructure and APIs that let developers create powerful agentic applications on the Claude API — including Claude Managed Agents, our managed platform for deploying and running agents in production. Your work spans the primitives agent developers depend on: tool use, multi-step reasoning, durable sessions and environments, and long-running task execution that lets Claude take actions and accomplish complex goals on a user's behalf. You'll make this platform ready for the largest enterprises to adopt, and partner with research to bring cutting-edge agent capabilities into production. Auth & Identity: We build and maintain the critical infrastructure and control interfaces that power identity and authentication across Anthropic's product suite. We work closely with product teams, security, support, and trust & safety as customers. We create scalable solutions for user authentication, authorization, role-based access control, and single sign-on that form the backbone of our company's identity management operations. We maintain a user-centric approach, building reliable systems that our users and company can depend on as we tackle complex challenges at the intersection of security, scalability