Software Engineer - Product Security

The role

You will design and ship authentication, authorization, and multi-tenant isolation code. You will solve AI security problems, build privacy-preserving systems, and own application security across the product, APIs, and browser.

What you will do

• Own authorization and identity in the product.
• Design and ship authentication, authorization, and multi-tenant isolation code.
• Solve AI security problems like untrusted model output and sandboxed code execution.
• Build privacy-preserving systems and implement the data lifecycle in code.
• Make the product explain itself by emitting security-relevant events as durable records.
• Ship security-sensitive changes end to end, including production migrations.
• Own application security across the product, APIs, and the browser.
• Lead threat modeling and own fixes in the codebase.

Required qualifications

• 6+ years of software or security engineering experience building and shipping production systems at scale.
• Strong proficiency in a modern backend language.
• Solid data fundamentals including modeling and querying Postgres.
• Working fluency with cryptographic application primitives.
• Multi-tenant systems experience where isolation is a hard requirement.
• Threat modeling and secure architecture design on systems you did not build.
• The ability to turn legal and policy requirements into working systems.
• Clear communication to build alignment across engineering, product, legal, and leadership.
• Comfort with ambiguity.
• Ability to walk through recent hands-on production code in depth.
• Application and API security knowledge regarding authorization models, session and token handling, and multi-tenant isolation.

Nice to have

• Exposure to securing AI, agentic, or LLM-backed systems in production, or the appetite to go deep on it quickly.
• Offensive instincts.

Benefits

• Competitive compensation aligned to the markets where team members are based.
• Comprehensive health and wellness benefits, including medical, dental, vision, and additional support programs.
• The opportunity to work on cutting-edge AI with a small, mission-driven team.
• A culture that values transparency, trust, and community impact.

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, the company builds the foundation for understanding and shaping AI.