Founding Security Engineer

Our client is a fast-growing, Sequoia-backed AI research platform used by leading technology companies and major enterprises. Its product autonomously designs customer interviews, recruits participants, and analyzes responses, helping teams turn complex research questions into useful insight in hours rather than weeks. This is the company's first dedicated security engineering hire. You will report directly to the co-founder and CTO, define the security architecture, and build a practical security program for a platform that holds sensitive voice, face, and device data at significant scale. The role begins as a senior individual contributor position with the opportunity to build a team as the company grows. What you'll do • Define and build security architecture across the LLM pipeline, cloud infrastructure, and customer-facing product. • Partner with engineering pods on threat modeling, vulnerability discovery, and secure design before features ship. • Harden multi-tenant isolation and support multi-region data residency with the infrastructure team. • Own penetration tests, vulnerability scans, remediation programs, and practical security policies. • Manage internal device, access, identity, and security operations. • Serve as the technical authority for audits, customer questionnaires, and enterprise security reviews. • Build the roadmap for a durable security program that can scale with Fortune 500 customers. • 7+ years of security engineering experience. • A software engineering or computer science foundation before moving into security. • Strong application, infrastructure, and cloud security judgment. • Demonstrated ability to find vulnerabilities in code and system designs, then work directly with engineers on practical remediation. • Experience building or materially shaping a security program in a fast-moving technology company. • Comfort operating independently while communicating clearly with technical leaders and enterprise customers. Bonus points • Experience as the first or founding security engineer at a high-growth startup. • Familiarity with LLM security, sensitive research data, multi-tenant SaaS, or regional data-residency systems. • Experience with TypeScript, identity and access management, penetration testing, or enterprise security reviews. • Interest in growing from a senior individual contributor into a security leader who can build a team. • $230K-$300K base salary. • Competitive equity. • Visa transfers and new visa sponsorship may be available, including H-1B and TN cases. • High-impact ownership as the founding security hire. This role is on-site five days per week in San Francisco, California.