• Own product security reviews end-to-end: threat modeling, security architecture review, and design consultation for new features and services • Lead security design reviews for Flex's payment processing, account management, and partner integration platforms • Drive the secure development lifecycle (SDLC) across engineering teams — shifting security left through tooling, process, and education • Perform application security assessments, code review, and penetration testing for critical product surfaces • Respond to and investigate complex security incidents; lead post-incident analysis and remediation • Build security automation and tooling to scale product security reviews (AI-assisted review tools, SAST/DAST pipeline integration) • Translate complex security concepts for cross-functional stakeholders and drive security adoption across product and engineering • Contribute to security standards, frameworks, and architectural patterns that guide organization-wide practices