Senior Security Engineer, Platforms & AI

About the Role We're looking for a hands-on Senior Security Engineer to own the technical security posture of our platform, infrastructure, and AI-driven systems. You'll spend most of your time in the systems themselves: hardening infrastructure, closing vulnerabilities, and building the guardrails that keep our AI-driven workflows safe. Following our recent Series A, we're scaling rapidly and investing deeply in platform security, AI safety, and operational resilience. This is a builder's role, not a policy role. You'll work closely with Engineering to secure production systems, find weaknesses, and keep our monitoring and incident response sharp as we scale. As a remote-first company, we welcome applicants based anywhere in the United States or Canada. You'll join a high-ownership, high-trust engineering culture where self-starters thrive and autonomy is the natural state of work. Key Responsibilities Security Engineering & System Hardening Secure and harden cloud infrastructure, applications, APIs, internal systems, and operational workflows. Implement and maintain security controls across production environments, CI/CD pipelines, cloud infrastructure, and internal tooling. Work directly with engineering teams to remediate vulnerabilities and improve secure development practices. Ensure encryption, secrets management, logging, monitoring, and access controls are properly implemented and continuously maintained. Design and improve security architecture across cloud-native and distributed systems. Build scalable security processes that integrate directly into engineering and operational workflows. Vulnerability Management & Offensive Security Continuously identify, assess, prioritize, and remediate security vulnerabilities across infrastructure, applications, APIs, and operational systems. Proactively search for weaknesses through vulnerability scanning, penetration testing, adversarial testing, threat modeling, and manual security reviews. Coordinate remediation e