Founding Product Security Engineer

About the Company

Arena is the platform for evaluating how AI models perform in the real world. Founded by researchers from UC Berkeley's SkyLab, we're on a mission to measure and advance the frontier of AI for real-world use, and to build the foundation for everyone to understand, shape, and benefit from it.

Responsibilities

• Own the product security vision for Arena, ensuring security and trust are core to every stage of our product lifecycle
• Design and implement identity, authentication, authorization, and account-lifecycle systems
• Secure the model inference path end-to-end, including provider credential handling and API gateway protections
• Lead threat modeling and security architecture reviews for new and existing product features
• Collaborate with infrastructure and product engineering to design secure APIs and data flows
• Improve developer velocity by creating secure-by-default frameworks and tooling
• Partner with incident response to assess, contain, and remediate security events
• Mentor engineers across the company on secure coding practices and operational security

Requirements

• 6+ years of experience in software engineering or security engineering
• Staff-level experience securing large-scale, user-facing platforms
• Strong experience with threat modeling and secure architecture design
• Hands-on experience building security features into production systems at scale
• Deep knowledge of authentication, authorization, and identity systems
• Strong knowledge of distributed systems security and API security
• Proficiency in Node.js, TypeScript, Python, or Go

Preferred Qualifications

• Experience securing AI/ML inference paths or high-volume public APIs
• Experience building behavioral-signal or fingerprinting platforms
• Contributions to open-source security tools or research
• Experience leading security incident response end-to-end