Security engineer, application security (UK) WRITER United Kingdom Middle 4h ago

Remote Genie; United Kingdom; Hybrid; GBP 70,000 - 110,000; Full time

Benefits offered by this job

Medical and dental insurance

Paid parental leave

Fertility support

Company pension scheme

Wellness stipend

Learning and development stipend

Company stock options

Team off-sites

Job summary

WRITER is seeking a Security Engineer, Applications to join our enterprise-grade AI platform. You will help build security foundations for AI systems powering global brands, working at the intersection of application security, AI infrastructure, and developer enablement.

You will drive threat modeling, secure architecture, CI/CD security tooling, code reviews, and secure coding standards across engineering teams.

Qualifications

• 4+ years of hands-on experience in application security engineering.
• Experience securing large-scale production systems.
• Familiarity with SAST/DAST and DevSecOps.
• Ability to communicate security concepts to technical and non-technical audiences.

Responsibilities

• Conduct threat modeling of AI architectures and secure features.
• Design secure architectures for new features and ensure security shapes product decisions.
• Establish and maintain SAST/DAST in CI/CD pipelines, and perform security code reviews.
• Lead security assessments and penetration testing of applications, AI services, and APIs.
• Develop reusable security patterns and libraries to enable engineers securely by default.
• Stay ahead of AI/ML security threats and build defenses.

Skills

Threat modeling

Security code reviews

Penetration testing

Secure coding practices

DevSecOps

Communication skills

Automation / scripting

Tools

SAST

DAST

CI/CD pipelines

Security testing frameworks

Job description

Security engineer, application security (UK)

WRITER

United Kingdom Middle Cybersecurity 1d ago

About this role

About WRITER

WRITER is where the world’s leading enterprises orchestrate AI-powered work. Our vision is to expand human capacity through superintelligence. And we’re proving it’s possible – through powerful, trustworthy AI that unites IT and business teams together to unlock enterprise-wide transformation. With WRITER’s end-to-end platform, hundreds of companies like Mars, Marriott, Uber, and Vanguard are building and deploying AI agents that are grounded in their company’s data and fueled by WRITER’s enterprise-grade LLMs. Valued at $1.9B and backed by industry-leading investors including Premji Invest, Radical Ventures, and ICONIQ Growth, WRITER is rapidly cementing its position as the leader in enterprise generative AI.

Founded in 2020 with office hubs in San Francisco, New York City, Seattle, Austin, Chicago, and London, our team thinks big and moves fast, and we’re looking for smart, hardworking builders and scalers to join us on our journey to create a better future of work with AI.

About the role

This is where security meets innovation at enterprise scale. As a security engineer, applications at WRITER, you’ll be building the security foundations that protect the AI systems powering some of the world’s most recognizable brands. 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.

The opportunity is massive: you’ll help define how enterprise AI applications are secured, from threat modeling our LLM architectures to building automated security controls that scale across our growing platform. This isn’t about saying "no"—it’s about finding creative ways to say "yes, and here’s how we do it securely." You’ll tackle challenges that most security engineers never encounter: securing AI agents, protecting training data pipelines, and designing controls for systems that didn’t exist a few years ago.

This role is hybrid from our London office, reporting to the head of security engineering.

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

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. You care deeply about reducing risk while considering velocity of engineers.

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—you can explain why something matters and motivate teams to action

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 (building strong relationships across teams), Challenge (pushing the boundaries of what’s possible in AI security), and Own (taking end‑to‑end responsibility for the security of our platform)

Comprehensive medical and dental insurance

Paid parental leave for all parents (16 weeks)

Fertility and family planning support

Early‑detection cancer testing through Galleri

Competitive pension scheme and company contribution

Wellness stipend for gym, massage/chiropractor, personal training, etc.

Learning and development stipend

Company-wide off‑sites and team off‑sites

Competitive compensation and company stock options