Application Security Engineer, Generative AI

Liftoff is a leading AI-powered performance marketing platform for the mobile app economy. Our end-to-end technology stack helps app marketers acquire and retain high-value users, while enabling publishers to maximize revenue across programmatic and direct demand. Liftoff's solutions, including Accelerate, Direct, Monetize, Intelligence, and Vungle Exchange, support over 6,600 mobile businesses across 74 countries in sectors such as gaming, social, finance, ecommerce, and entertainment. Founded in 2012 and headquartered in Redwood City, CA, Liftoff has a diverse, global presence. About Liftoff Security Team The Liftoff Security team protects Liftoff's customers, users, and employees. We architect Liftoff's security posture, build the tools and systems that defend it, and partner with engineering teams as they ship new products and features. Our work spans the entire stack — infrastructure, web, mobile, and IT — and we approach security from a software engineering standpoint, scaling our impact through automation and well-designed tools. This individual contributor role reports to the Director of Security and owns application security for GenAI, Creative GenAI, and emerging businesses. Application security is the primary focus; you will also contribute across cloud and infrastructure security, support Accelerate and MX as priorities change, and share the team's on-call and incident-response work. Responsibilities • Establish secure software development standards and integrate security into engineering design and development. • Create self-service paths for engineering teams to build and deploy securely through documented review workflows, reusable tools, and secure design patterns. • Perform design and code reviews, threat modeling, and security assessments for GenAI, Creative GenAI, and emerging businesses, including sandbox design and isolation. • Partner with stakeholders across the organization to build a culture of security-minded builders. • Triage incoming security issues, prioritize vulnerabilities by risk, and work with engineering teams through timely remediation and verification. • Assess vendors and AI tools to ensure their security controls and product features support secure employee use. • Share the security team's on-call and incident-response rotation, including occasional off-hours response. • Conduct blameless post-incident reviews, document findings, and follow through on remediation. • Build maintainable security tools and automation, including an AI-assisted code-security triage pilot that produces actionable findings at a false-positive rate engineering will accept. • Partner with Detection & Response to turn application-security findings and threat models into detection improvements and response guidance. • Contribute across application, cloud, and infrastructure security as priorities change, including Accelerate and MX. Minimum qualifications • 5+ years of relevant experience in security engineering or software engineering. • Excellent judgment in prioritizing security efforts using a risk-based approach. • Experience partnering with cross-functional teams to deliver security improvements and help engineers choose practical fixes. • Write production-quality code for security tools and automation, review pull requests, and navigate large, unfamiliar codebases. • Strong understanding of secure software design, application and API security, authentication and authorization, threat modeling, and code review. • Experience assessing cloud and infrastructure security and contributing beyond a primary application-security specialty. • Ability to quickly understand complex engineering systems and architecture. • Practical software engineering habits: testing, observability, version control, peer code review, continuous integration, and blameless postmortems. • Strong technical writing: design documents, proposals, runbooks, and post-incident reviews that support engineering decisions. Explain security risks and tradeoffs clearly in writing and conversation. • Willingness to share the security team's on-call and incident-response responsibilities, including occasional off-hours response. Desirable qualifications • Experience with Go, Python, Clojure, or JavaScript; ability to work across languages matters more than a specific language. • Experience securing GenAI applications, designing sandboxes, or evaluating AI-assisted security tools and their output. • Experience scaling cloud security or working with high-velocity software engineering teams, mobile advertising, or other high-volume SaaS environments. Why This Role is Exciting • High Visibility & Impact: Be a core member of a security team with significant influence. • Diverse & Challenging Projects: Engage in various domains including product security, vendor security, corporate security, and infrastructure security. • Security-Conscious Engineering Culture: Collaborate with engineering teams that value