Staff Product Security Engineer

We are seeking an experienced and motivated Staff Product Security Engineer to join our growing Security team. This individual will be responsible for the end-to-end security of our consumer products, digital platform and an emerging hardware device line. The Staff Product Security Engineer will drive security review, threat modeling programs, lead penetration testing, manage PSIRT operations, champion secure AI adoption and establish security guardrails for AI powered products and AI assisted development workflows within a highly regulated financial services environment.

This role reports to the Senior Manager of Product Security.

Your day-to-day:

• Lead security architecture/design review and threat modeling sessions with product and engineering teams using STRIDE, PASTA and attack tree methodologies.
• Translate threats into actionable, risk-rated engineering remediations prioritized by severity.
• Conduct hands-on penetration testing and security assessments across our full product stack producing actionable reports for engineering and leadership.
• Red-Team our AI powered products and development tools to test for prompt injection, data exfiltration, MCP server exploitation, and tool misuse. Probe AI guardrails to ensure they hold. Experience with product security tools such as Burp Suite, Metasploit, Kali Linux, Postman, etc.
• Drive PSIRT Operations by triaging incoming vulnerability reports, leading technical investigations, coordinating remediation with engineering, scoring severity (CVSS), managing coordinated disclosure with external researchers and on-call incidents. This includes managing zero day findings, driving remediation, collaborating with engineering to patch or mitigate with compensating controls.
• Shape the posture of our AI assisted development environment defining and enforcing enterprise policies for claude and cursor.
• Partner across the organization, sitting in design review with architects, advising product managers and engineering teams on security and compliance implications of new features, briefing executives on emerging AI threats, mentoring junior security engineers and collaborating with the AI team on securing ML pipelines.
• Champion Security Culture by running developer training on secure coding with AI assistants, evangelizing security by design for products and ensuring every engineer understands that product security is an enabler and not a gate.

What you’ll bring to the team:

• 10+ years of product security experience spanning application security, cloud security, and secure SDLC. you will have full SDLC experience from design through development, deployment and incident response.
• Expert level Threat Modeling using STRIDE, PASTA or equivalent across web, mobile, cloud, embedded and AI systems.
• Hands-on penetration testing skills across applications, API, cloud infrastructure, and hardware/firmware. You think like an attacker and you can provide it through published research, CVE discoveries, bug bounty results or red-team engagements.
• PSIRT operational experience from vulnerability intake and triage. You are fluent in CVE, CVSS, FIRST PSIRT frameworks.
• Deep hands down AI security expertise and expert level understanding of OWASP Top 10 for LLM, API, Web, Mobile and have practical experience with MITRE.
• Strong hands-on experience in security tools SAST, DAST, SCA, and securing AI development tools specifically Claude and Cursor.
• You understand MCP security risks and know how to architect enterprise guardrails that enable safe AI-assisted development. You have defined policies for AI generated code, secrets scanning, and DLP for outbound AI traffic.
• Strong programming ability and capability to review code, build security tools, automate workflows and be credible with the engineering teams you partner with.
• Deep technical knowledge of CI/CD pipeline and relevant tools for web and mobile applications.
• Strong knowledge of programing language & frameworks (i.e. Node.js, Java/Kotlin, React, Redux, Swift, SwiftUI), cloud technologies and infrastructure (i.e. AWS, GCP, Kubernetes, Ambassador, Helm), and databases (i.e. MySQL, DynamoDB, Redis)
• Ability to influence without authority, mentor without managing , and communicate complex risks in a language that resonates with engineers, product managers, legal and compliance and executives alike.

Preferred experience:

• Hardware and embedded security experience with knowledge of secure boot, firmware integrity, hardware root of trust, and IoT threat modeling experience.
• Experience in the Financial industry, knowledge of PCI DSS, COPPA or demonstrated ability to learn regulated domains quickly.

Work perks at Greenlight:

• Medical, dental, vision, and HSA match
• Paid life insurance, AD&D, and disability benefits
• Traditional 401k with company match
• Unlimited PTO
• Paid company holidays and pop-up bonus holidays
• Professional development stipends
• Mental health resources
• 1:1 financial planners
• Fertility healthcare
• 100% paid parental and caregiving leave, plus cleaning service and meals during your leave
• Flexible WFH, both remote and in-office opportunities
• Fully stocked kitchen, catered lunches, and occasional in-office happy hours
• Employee resource groups