← All roles

Security engineer, application security (UK)

WRITER· EPD
Apply on company site
Hybrid (London, UK)Full-timePosted 4w ago

About the role

Security engineer role focused on building security foundations for WRITER’s AI platform, integrating security into development, threat modeling LLM architectures, and designing scalable security controls across applications, AI infrastructure, and data pipelines. Hybrid role based in London.

Responsibilities

  • 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—not after the fact
  • Own and evolve our application security program including establish and maintain SAST/DAST scanning in CI/CD pipelines, conducting security code reviews for critical changes, and building automation that catches vulnerabilities before they reach production
  • Partner with engineering teams to establish and champion secure coding standards, creating reusable security patterns and libraries that make it easier for developers to build securely by default
  • Design and recommend security features and products that help secure customer environments. You are the advocate and the vision for how we protect and secure customers.
  • Integrate and leverage AI agents to help increase velocity for the security team and the overarching engineering org to ensure that we are proactive in minimizing risk while we build products
  • Lead security assessments and penetration testing of WRITER's applications, AI services, and APIs, identifying vulnerabilities across our tech stack and working collaboratively with teams to remediate 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 against novel risks

Qualifications

  • 4+ years of hands-on experience in application security engineering, with a proven track record of securing large-scale production systems—bonus points if you've worked in fast-growing startups or high-growth environments
  • 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, understanding both business logic and security implications
  • Knowledge of security tools and methodologies including SAST/DAST solutions, vulnerability management platforms, security testing frameworks, and DevSecOps practices—you know which tools to use and when automation beats manual review
  • Excellent communication skills that allow you 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 rather than create bottlenecks—you understand that security enables the business, not blocks it
  • Alignment with WRITER's values of Connect, Challenge, and Own

Skills

Required:Threat modelingSAST/DAST in CI/CDSecure coding standardsPenetration testing
Nice to have:DevSecOps

Benefits

  • Generous PTO, plus company holidays
  • Comprehensive medical and dental insurance
  • Paid parental leave for all parents (16 weeks)
  • Fertility and family planning support
  • Competitive pension scheme and company contribution
  • Annual work-life stipends for: wellness, learning and development
  • Company-wide off-sites and team off-sites
  • Competitive compensation and company stock options
Last updated Oct 22, 2026. Interested? Apply on the company site.

About WRITER

End-to-end agent builder platform that unites IT & business

Eliminate silos with an end-to-end agent builder platform, designed for collaboration—without compromise. Build, activate, and supervise agents.

AI platformsAI research labcollaborative toolsenterprise technologygenerative AIindustry solutionsliquid-ai-recruiting-target
Company profileWebsite

More open roles at WRITER