Staff + Software Security Engineer, Secure Frameworks

Job Overview

You will design, build, and run security foundations used across Anthropic's fleet, from threat model through production, on-call, and adoption. Much of the work is greenfield: our infrastructure is growing quickly, and the timelines are compressed, so you will help define the architecture rather than inherit it.

Responsibilities

• 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
• Scope, design, and build security services and libraries end-to-end, maintain them in production, and drive through ambiguous technical problems with minimal oversight
• Build and operate the zero-trust access gateway that fronts Anthropic's internal services
• Design and roll out authorization frameworks so services enforce least privilege consistently instead of each inventing its own access controls
• Own cryptographic frameworks and libraries
• Mentor engineers, contribute to hiring, and grow security engineering culture across Anthropic

Requirements

• 8+ years of software engineering experience building security-relevant systems in production, including leading complex initiatives independently
• Strong programming skills in Go, Rust, or Python
• Deep understanding of authentication and authorization systems: OAuth 2.0 / OIDC, JWTs, service-to-service auth, policy-based access control
• Hands-on experience with PKI, X.509, mTLS, and workload identity
• Working knowledge of applied cryptography: choosing and composing primitives correctly, key management, and the ways libraries fail in practice
• Experience shipping and operating high-reliability services on Kubernetes across cloud and on-prem environments, including being on-call for them
• A track record of bringing clarity and ownership to ambiguous technical problems and driving them to resolution across teams
• A strong sense of developer experience
• Clear communication across all levels of the organization
• Passion for AI safety and the role security engineering plays in building trustworthy AI systems

Benefits

• Competitive compensation and benefits
• Optional equity donation matching
• Generous vacation and parental leave
• Flexible working hours
• Lovely office space

Location

San Francisco, CA | New York City, NY | Seattle, WA