Founding Security Engineer

About the role

This is a founding security role at a Sequoia-backed Series B company that has grown 20x year-over-year in revenue. The position involves building the entire security program from scratch with greenfield ownership and direct reporting to the co-founder/CTO. The company works with elite engineering teams and serves world-class customers including Anthropic, Google, Microsoft, and Robinhood.

Why this role

• Founding security role with real impact at a high-growth company
• Direct report to the CTO with high visibility and autonomy
• Opportunity to build out a team and deepen scope as the company scales

What you will do

• Define and build the security architecture from the ground up across the LLM pipeline, infrastructure, and product
• Take ownership of the entire security program as the first dedicated security hire
• Work closely with engineering pods to identify vulnerabilities, run threat modeling, and ensure secure design patterns
• Harden multi-tenant isolation and collaborate with the infrastructure team on multi-region data residency
• Manage pen tests, vulnerability scans, and write lightweight policies to maintain compliance and security
• Own internal IT, including devices, access, and identity
• Serve as the technical ground truth behind audits, questionnaires, and enterprise security reviews
• Contribute to and help evolve the security roadmap as the company scales with Fortune 500 customers

What we are looking for

• 7 to 15 years of experience in security engineering or software engineering transitioning to security
• Hands-on experience spanning application security and infrastructure security
• Proven track record of building a security program from scratch
• Expertise in threat modeling and vulnerability assessment, including pen tests, vulnerability scans, and risk prioritization
• Ability to read and review code for security vulnerabilities (not purely GRC/compliance)
• Experience in cloud security architecture and multi-tenant isolation