Staff Application Security Engineer

ABOUT THE ROLE The Staff Application Security Engineer will play a critical role in defining the technical vision and long-term security architecture for the Brex platform. As a technical leader, you will drive the strategic direction of our secure product lifecycle and vulnerability management programs. WHAT YOU'LL DO As a Staff Application Security Engineer, you will lead the technical vision and strategic roadmap for the Application Security team, aligning security objectives with Brex's enterprise growth and high-velocity engineering metrics. You will establish technical standards and secure defaults across the entire engineering organization, fostering a culture of collaborative security excellence and bridging product platforms, infra, and trust. You will also architect and secure novel AI/ML and agentic workflows, applying cutting-edge practices to mitigate risks such as prompt injection, model manipulation, and data poisoning. Additionally, you will mentor and coach engineers within the team and across the broader organization, guiding technical growth, helping individuals level up their security expertise, and accelerating team delivery. WHAT YOU'LL NEED To be successful in this role, you will need 8+ years of experience in Application Security, Product Security, or software engineering with a primary focus on offensive and defensive application security. You should have a proven track record of technical leadership and team mentorship on complex, multi-quarter security engineering initiatives in a fast-paced environment. You should also have deep proficiency and technical expertise in AI security, including hands-on experience securing agentic architectures, LLM gateways, and evaluating adversarial AI vectors. Strong systems-thinking capabilities with extensive experience defining secure product development lifecycles, threat modeling complex topologies, and cloud-native container security (AWS, Kubernetes) are also required. Proficiency in Python, Go, or similar languages to architect internal tooling, pipeline automation, and advanced detection/scanning engines is essential. Exceptional written and verbal communication skills, with a demonstrated ability to navigate ambiguity, influence technical leaders, and manage up and out across EPD organizations, are also necessary. WHY REMOTE As a Staff Application Security Engineer at Brex, you will have the flexibility to work from home and will be required to be in the office 3 days a week (Monday, Wednesday, and Thursday). This hybrid environment combines the energy and connections of being in the office with the benefits and flexibility of working from home. BENEFITS Brex offers a comprehensive benefits package, including a competitive salary, health insurance, and education stipend. You will also have access to a flexible schedule, allowing you to balance your work and personal life.