Security engineer, application security (UK)
About this role
Conducting threat modeling sessions with product teams and designing secure architectures for new features forms the core daily focus of the security engineer. Professionals in this position embed security into the DNA of the AI platform by establishing SAST and DAST scanning in CI/CD pipelines, conducting security code reviews, and leading penetration testing across applications, AI services, and APIs.
Writer builds an end-to-end platform enabling major enterprises to orchestrate AI-powered work through trustworthy LLMs and AI agents. This role exists to define how enterprise AI applications are secured while maintaining engineering velocity and developer enablement. Ideal candidates possess a builder mindset, strong technical expertise in programming languages, and a collaborative approach to partnering with engineering teams.
What you will do
- Conduct threat modeling sessions with product teams to design secure architectures for new features from inception.
- Own and evolve the application security program by establishing SAST and DAST scanning in CI/CD pipelines.
- Partner with engineering teams to champion secure coding standards and create reusable security patterns.
- Design and recommend security features and products to protect customer environments.
- Integrate AI agents to increase velocity and minimize risk for the security and engineering organizations.
- Lead security assessments and penetration testing of applications, AI services, and APIs to remediate issues at scale.
- Design and implement security controls for data pipelines, model training environments, and customer-facing AI agents.
- Research attack vectors specific to LLMs and generative AI to build proactive defenses against emerging threats.
What you need
- Bring four or more years of hands-on experience in application security engineering with a track record of securing large-scale production systems.
- Demonstrate a solid understanding of developer experience and workflows to reduce risk while maintaining delivery velocity.
- Possess technical expertise in at least two programming languages such as Python, Java, Go, or JavaScript/TypeScript.
- Show knowledge of security tools and methodologies including SAST/DAST solutions, vulnerability management, and DevSecOps practices.
- Exhibit excellent communication skills to translate complex security concepts into clear recommendations for various audiences.
- Maintain a builder mindset focused on automation, scaling, and empowering teams rather than creating operational bottlenecks.
Nice to have
- Experience working in fast-growing startups or high-growth environments
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 and learning
Skills and tech stack
Questions candidates ask
What is the work location and policy for this role?
This role is hybrid from our London office, reporting to the head of security engineering. Founded in 2020 with office hubs in San Francisco, New York City, Seattle, Austin, Chicago, and London, our team thinks big and moves fast.
What kind of projects will I work on regarding AI security?
You will 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 includes threat modeling our LLM architectures and building automated security controls.
What programming languages and technical skills are required?
You need technical expertise in at least two programming languages, specifically Python, Java, Go, or JavaScript/TypeScript. Candidates also require knowledge of security tools and methodologies including SAST and DAST solutions, vulnerability management platforms, and DevSecOps practices.
What benefits are provided for UK full-time employees?
UK full-time employees receive generous PTO, comprehensive medical and dental insurance, and 16 weeks of paid parental leave. Additional perks include fertility support, a competitive pension scheme, and annual work-life stipends for wellness and learning.