Staff security engineer, application security

About Writer

WRITER is where the world's leading enterprises orchestrate AI-powered work. Our vision is to expand human capacity through superintelligence. Hundreds of companies like Mars, Marriott, Uber, and Vanguard are building and deploying AI agents grounded in their company's data and fueled by WRITER's enterprise-grade LLMs.

About the Role

As a Staff Security Engineer, Application Security at WRITER, you'll build the security foundations that protect the AI systems powering global enterprises. You'll work at the intersection of application security, AI infrastructure, and developer enablement—partnering with engineering teams to embed security into every line of code while ensuring our platform remains both powerful and trustworthy.

This role is hybrid from our New York City, San Francisco, or Seattle offices, reporting to the Head of Security Engineering.

What You'll Do

• Build security into the DNA of our AI platform by conducting threat modeling sessions with product teams, designing secure architectures for new features, and ensuring security considerations shape product decisions from day one
• Own and evolve our application security program including establishing and maintaining SAST/DAST scanning in CI/CD pipelines, conducting security code reviews for critical changes, and building automation that catches vulnerabilities before production
• Partner with engineering teams to establish and champion secure coding standards, creating reusable security patterns and libraries
• Design and recommend security features and products that help secure customer environments
• Integrate and leverage AI agents to help increase velocity for the security team and the overarching engineering organization
• Lead security assessments and penetration testing of WRITER's applications, AI services, and APIs, remediating issues at scale
• Design and implement security controls for protecting data pipelines, model training environments, and customer-facing AI agents
• Stay ahead of emerging threats in the AI/ML security landscape, researching attack vectors specific to LLMs and generative AI, and proactively building defenses

What You Need

• Minimum 4 years of hands-on experience in application security engineering, with a proven track record of securing large-scale production systems
• Understanding of developer experience and developer workflows for shipping features and products
• Technical expertise in at least two programming languages (Python, Java, Go, JavaScript/TypeScript) and the ability to read and review code across multiple languages
• Knowledge of security tools and methodologies including SAST/DAST solutions, vulnerability management platforms, security testing frameworks, and DevSecOps practices
• Excellent communication skills to translate complex security concepts into clear recommendations for both technical and non-technical audiences
• A builder's mindset that looks for opportunities to automate, scale, and empower
• Alignment with WRITER's values of Connect, Challenge, and Own
• Open to Mid, Sr., and Staff level candidates