Security Engineer, Applications (AI Security)

Location: Hybrid from the London office, UK

Company

Writer builds an enterprise AI platform that enables companies to create and deploy AI agents grounded in company data and powered by enterprise-grade LLMs.

What you will do

• Conduct threat modeling with product teams and design secure architectures for AI platform features.
• Own and evolve the application security program, including SAST/DAST scanning in CI/CD, security code reviews, and vulnerability automation.
• Develop secure coding standards, reusable security patterns, and libraries with engineering teams.
• Design security features and controls for customer environments, data pipelines, model training environments, and customer-facing AI agents.
• Lead application, AI service, and API security assessments and penetration testing, coordinating remediation at scale.
• Research emerging LLM and generative AI attack vectors and build proactive defenses, including AI-assisted security workflows.

Requirements

• 4+ years of hands-on experience in application security engineering and securing large-scale production systems.
• Expertise in at least two of Python, Java, Go, and JavaScript/TypeScript, with the ability to review code across multiple languages.
• Knowledge of SAST/DAST, vulnerability management, security testing frameworks, and DevSecOps practices.
• Understanding of developer workflows and the ability to balance security risk reduction with engineering velocity.
• Strong communication skills for explaining security risks and recommendations to technical and non-technical audiences.
• Builder mindset and alignment with Writer’s values of Connect, Challenge, and Own.

Culture & Benefits

• Hybrid work from the London office with company-wide and team off-sites.
• Generous paid time off and company holidays.
• Medical and dental insurance, plus 16 weeks of paid parental leave for all parents.
• Fertility and family planning support and early-detection cancer testing through Galleri.
• Competitive pension scheme, company contribution, and company stock options.
• Annual wellness and learning and development stipends.