Founding Security Systems Engineer

Role overview Build and operate security-critical systems that evaluate AI agents’ proposed actions before they run. The role focuses on turning authorization controls into dependable product capabilities, integrating them into customer environments, and taking responsibility for their behavior in production. It is a hands-on founding engineering position, with a possible path to broader technical leadership based on demonstrated results.

Responsibilities - Design, build, test, deploy, and operate backend and runtime components that enforce security decisions. - Improve authorization policy, identity and instruction provenance, evidence integrity, and attestation for high-impact actions. - Develop secure agent-harness capabilities for tool execution, identity propagation, human approval, sandbox boundaries, retries, timeouts, and evidence capture. - Maintain SDK, API, proxy, and MCP integration paths across Go, Rust, Python, and TypeScript. - Develop supply-chain controls for models and plugins, including signed manifests and artifact verification. - Integrate capabilities into design-partner environments and own their operation in production.

Benefits and work setup Full-time role open to candidates in New York City, the San Francisco Bay Area, and remotely in the U.S. or Canada. The distributed team expects periodic travel for customer work, events, and team gatherings. The hiring description asks applicants to share an example of a security-sensitive production system they built or operated and how they verified its critical properties.