Lead Security Engineer With harnesses and PoCs.- 12+ Years

Role: Lead Security Engineer Location: San Jose, CA (5 days a week) Job Summary: Lead Security Engineer to support the Search Engineering team with vulnerability management, threat modeling, secure architecture, and validation of automated security fixes. Responsibilities Manage vulnerability lifecycles and support secure architectural practices. Document trust boundaries, data flows, attack surfaces, and architectural entry points for high-priority services. Maintain threat models and security profiles in centralized repositories. Review security scanner findings, classify severity, and evaluate exception requests against security policies. Build test environments and harnesses to reproduce vulnerabilities and validate PoCs. Supervise and validate code patches generated by automated remediation agents. Execute tests and inspect code changes to identify regressions or incorrect fixes. Coordinate with product teams and code owners to move validated fixes through code review and production deployment. Required Skills Understanding of trust boundaries, attack surfaces, data flows, and threat modeling frameworks such as STRIDE and PASTA. Knowledge of CWE, CVE, OWASP Top 10, vulnerability severity, and SLA mapping. Ability to read and write code in at least two of the following: C++, Go, Java, Python. Experience building test harnesses and PoCs. Strong code review skills, including identifying regressions and unreliable or incorrect code changes. Knowledge of secure coding standards and practices. Preferred Skills Threat model reviews for large distributed or microservice architectures. Vulnerability queues, automated scanning tools, and compliance exception reviews. Fuzzing, unit testing frameworks, sandbox execution, and cross-boundary debugging. Prompt tuning for automated code generation tools, differential testing, and patch validation.