Staff + Software Security Engineer (Secure Frameworks)

Join Anthropic, a leading AI safety and research company, as a Staff Software Security Engineer. In this role, you will be part of the Secure Frameworks team, responsible for building shared security libraries and frameworks that the rest of the company relies on. You will collaborate closely with various teams across Anthropic to establish critical security foundations, including workload identity and authorization, cryptographic frameworks, and a centralized access proxy. Your mission will be to make secure practices easy and to prevent vulnerabilities through careful design. You will have the opportunity to design, build, and run security foundations used across Anthropic's fleet, and much of the work will be greenfield, allowing you to define the architecture.

• Design, build, and run security foundations used across Anthropic's fleet, from threat model through production, on-call and adoption.
• Build critical security foundations including cryptographic frameworks, mTLS infrastructure, secure serialization, and authorization systems, designed to prevent entire classes of vulnerabilities.
• Partner with product, research, infrastructure, and other security teams to ensure frameworks integrate smoothly with lower-layer security controls.

• Working knowledge of applied cryptography: choosing and composing primitives correctly, key management, and the ways libraries fail in practice
• A strong sense of developer experience
• Experience shipping and operating high-reliability services on Kubernetes across cloud and on-prem environments, including being on call for them
• Clear communication across all levels of the organization
• Deep understanding of authentication and authorization systems: OAuth 2.0 / OIDC, JWTs, service-to-service auth, policy-based access control
• Passion for AI safety and the role security engineering plays in building trustworthy AI systems
• Hands-on experience with PKI, X.509, mTLS and workload identity
• A track record of bringing clarity and ownership to ambiguous technical problems and driving them to resolution across teams
• Strong programming skills in Go, Rust or Python
• 8+ years of software engineering experience building security-relevant systems in production, including leading complex initiatives independently
• We encourage you to apply even if you do not believe you meet every single qualification
• Familiarity with ML infrastructure (training, inference serving)
• Built or operated a zero-trust / BeyondCorp-style access gateway or identity-aware proxy
• Migrated a fleet to mTLS at scale, including certificate issuance and staged enforcement
• Built security frameworks or libraries adopted across an engineering organization, and done the work to drive that adoption
• Designed authorization systems using policy languages or relationship-based models
• Maintained or contributed to open-source cryptographic libraries