Staff+ Software Engineer, Backend

Anthropic•Seattle, WA

17h•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 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. 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 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

Nice To Haves

Served as a technical lead or architect on a product or API platform, owning both the technical vision and execution end-to-end
Experience designing and scaling APIs with a focus on developer experience, consistency, and reliability — including API design review processes
Deep experience building enterprise SaaS platforms, including permissions infrastructure, billing and pricing systems, or compliance frameworks for regulated industries (SO2, HIPAA)
Background in a specific industry vertical — financial services, healthcare, or legal technology — with a track record of building products that handle sensitive, domain-specific data
Experience partnering with ML/AI research teams to productize model capabilities or identify and address model failure modes in production
Experience building agentic systems, orchestration frameworks, or developer tools — including CLI tools, IDE integrations, or AI-assisted coding environments
Experience building products where adoption and activation are core challenges — instrumenting funnels, diagnosing drop-off, and shipping the product changes that close gaps
Experience designing operational processes (incident response, on-call rotations, postmortem review) for production systems serving large-scale developer or enterprise audiences