Staff security engineer, application security

WRITER is building an AI platform that needs security foundations designed for enterprise scale. In this Staff security engineering role, you will focus on application security while working at the intersection of AI infrastructure and developer enablement, helping teams ship securely without slowing delivery. The work spans secure architectures, CI/CD security automation, and defenses tailored to LLMs and generative AI.

Responsibilities

• Embed security into the AI platform by running threat modeling sessions with product teams, designing secure architectures for new features, and shaping security considerations into product decisions from the start.
• Own and evolve the application security program, including establishing and maintaining SAST/DAST scanning in CI/CD, performing security code reviews for critical changes, and building automation to detect vulnerabilities before they reach production.
• Partner with engineering teams to define and promote secure coding standards, and create reusable security patterns and libraries that support secure-by-default development.
• Design and recommend security features and products that help protect customer environments, serving as the advocate and vision for customer security.
• Integrate and leverage AI agents to increase velocity for the security function and the broader engineering organization, keeping risk minimized while products are built.
• Lead security assessments and penetration testing across WRITER applications, AI services, and APIs, identifying vulnerabilities across the stack and partnering on remediation at scale.
• Design and implement security controls for data pipelines, model training environments, and customer-facing AI agents.
• Stay ahead of emerging AI/ML security threats by researching LLM and generative AI attack vectors and building defenses for novel risks.

Requirements

• Minimum 4 years of hands-on application security engineering experience with a track record securing large-scale production systems, with a bonus for experience in fast-growing startups or high-growth environments.
• Strong understanding of developer experience and developer workflows, with a focus on reducing risk while maintaining engineering velocity.
• Technical expertise in at least two programming languages: Python, Java, Go, JavaScript/TypeScript, plus the ability to read and review code across multiple languages and assess both business logic and security implications.
• Knowledge of security tools and methodologies including SAST/DAST, vulnerability management platforms, security testing frameworks, and DevSecOps, with the ability to determine when automation outperforms manual review.
• Excellent communication skills to translate complex security concepts for technical and non-technical audiences, explaining impact and motivating action.
• A builder mindset focused on automation, scaling, and enabling teams without creating bottlenecks, understanding that security enables the business.
• Alignment with WRITER values of Connect, Challenge, and Own for end-to-end responsibility for platform security.
• Open to candidates at Mid, Sr., and Staff levels.

Technologies

• SAST, DAST, CI/CD
• Python, Java, Go, JavaScript/TypeScript
• DevSecOps
• LLMs, generative AI, AI agents
• APIs
• Vulnerability management platforms
• Security testing frameworks

Benefits

• Generous PTO, plus company holidays
• Medical, dental, and vision coverage for you and your family
• Paid parental leave for all parents (16 weeks)
• Fertility and family planning support
• Early-detection cancer testing through Galleri
• Flexible spending account and dependent FSA options
• Health savings account for eligible plans with company contribution
• Annual work-life stipends for wellness (gym, massage/chiropractor, personal training, etc.)
• Annual work-life stipends for learning and development
• Company-wide off-sites and team off-sites
• Competitive compensation, company stock options, and 401k

About the role

This role is positioned where security meets innovation at enterprise scale. You will build security foundations for applications at WRITER, protecting the AI systems behind services for well-known brands, while partnering across engineering to embed security into code and controls. The position is hybrid in Seattle, WA, reporting to the head of security engineering, and includes work such as securing AI agents, protecting training data pipelines, and designing controls for systems that have evolved quickly alongside modern AI.

Compensation: USD 183,000 - 240,000 per year.