Security Engineer - Application Security (Senior)

Role overview This is a senior application security role on the founding security team of an applied AI startup building agentic security products. The person hired will be an embedded security partner to engineering, owning application security testing, hardening the software supply chain, and turning security into scalable, automated guardrails across the SDLC while serving as the internal SME whose feedback shapes the product itself.

Responsibilities - Embed security into the SDLC through threat modeling, secure design reviews and practical secure-coding guidance that engineers actually adopt. - Own application security testing, including code review, SAST and DAST, triage and driving findings to remediation rather than just logging them. - Harden the software supply chain via dependency verification, safe dependency management and CI/CD pipeline security. - Build and automate security tooling and guardrails so security scales with the engineering organization. - Act as the internal security subject matter expert on product and workflow decisions, and serve as an early user of the platform. - Partner across teams on architecture and design to make security a default rather than an afterthought.

Requirements - Five or more years of security engineering experience focused on product or application security, holding work to high trust standards. - Strong hands-on engineering background with a track record of shipping code and automation, not only running process. - Comfort working in code across the stack, for example Python, Go or TypeScript. - Depth in application and product security: secure SDLC, threat modeling, code scanning and supply chain plus dependency security. - Fluency with the modern AI landscape and how it is changing the security threat and defense picture. - Ability to flex between strategic framing and deep technical execution, and comfort being an early security hire in a high-ownership, ambiguous startup environment.

Nice to have - Experience securing AI/ML products or agentic systems. - Background contributing to developer-enablement or security-champions programs. - Prior experience as an early security hire or building an AppSec function from scratch.

Benefits and work setup - For candidates based in California, the standard base salary range is $100,000 to $300,000 annually, with compensation determined by location, level, knowledge, skills and experience; certain roles may also include variable compensation, equity and benefits. - The employer states a commitment to building an inclusive, diverse team and does not discriminate on the basis of gender, ethnicity, sexual orientation, religion, civil or family status, age, disability or race.