Staff+ Software Engineer, Backend

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, and user experience.

Platform Distribution: 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.

Platform Safety: 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 teams across API, Claude.ai, and third-party platforms as customers, creating the systems for KYC/KYB, trust grant issuance and inheritance, and end-user verification that flow across every Anthropic surface. We sit at the intersection of trust, compliance, and product velocity, delivering the verification primitives that let Anthropic ship advanced model capabilities to the right users at massive scale.

You Might Be a Good Fit If You:

• Have 8+ years of relevant experience as a backend or product engineer, with a track record of leading complex, multi-month projects or teams as a tech lead or equivalent
• Have strong coding fundamentals and are comfortable working across backend systems, APIs, and integrations — and can reach into the frontend when needed to ship an effective solution
• Have led the design and delivery of large-scale backend systems in production that power high-adoption B2B or consumer facing products
• Are skilled at driving alignment across technical and non-technical teams; you communicate clearly, influence technical decisions beyond your immediate team, and help others ramp effectively on your systems
• Take a product-focused approach to your work work and care about building solutions that are robust, scalable, and easy to use
  Care deeply about investing in the mentorship and growth of your peers
• Have experience with distributed systems, API design, and cloud infrastructure at scale
• Thrive in fast-paced environments and can navigate ambiguity to find the highest-leverage path forward