Senior Application Security Engineer

Who you are

• Strong ability to write and review code (preferably in Python, TypeScript, Kotlin and Terraform), with a background in software development, SRE, DevOps, or practical security engineering
• In-depth understanding of securing AI/LLM applications, agentic tooling, and developer AI tools, including prompt injection mitigation, model integration risks, guardrails, telemetry, and the use of frontier models via APIs or locally
• Practical experience with agentic development using coding harnesses is essential
• Solid knowledge of major public cloud providers (preferably Google Cloud Platform, with Azure or AWS as beneficial) and network infrastructure
• Solid understanding of the Kubernetes ecosystem, Docker, and container security
• Experience implementing and managing security testing programs (SCA, SAST, DAST) within pipelines like GitHub Actions, alongside release packaging and artifact management
• Capability to develop secure, automated infrastructure using Terraform
• You enjoy learning about both the offensive and defensive aspects of security
• Ability to work collaboratively within enterprise-wide agile development environments
• Outstanding communication skills (both written and verbal), with the ability to explain complex vulnerabilities to technical teams and business stakeholders, share knowledge, and mentor colleagues

What the job involves

• As our Senior Application Security Engineer, you’ll empower our engineering and product teams to safely adopt AI and embed robust technical security controls directly into our services and workflows. By designing cloud-native security guardrails and automating processes, you’ll make the secure path the easiest path for our builders
• Your work will span our entire development lifecycle, protecting everything from agentic LLM integrations to the everyday tools we use. You’ll act as a trusted subject matter expert, collaborating closely across our product groups to foster a proactive, risk-conscious security culture. Through continuous mentorship and forward-thinking threat modelling, you’ll help us securely scale and drive a digital revolution in the global insurance market
• Provide practical implementation advice and guidance on securing AI-powered applications, aligning with frameworks like OWASP ASVS and the OWASP Top 10 for LLM Applications
• Lead threat modelling sessions for AI and agentic systems during the technical design phase using STRIDE and AI-specific frameworks
• Establish secure guardrails, allowlists, telemetry, and safe-by-default configurations for developer AI tooling
• Manage security testing workflows in the SDLC, utilizing scanners to check for standard and AI-specific risks such as prompt injection and data leakage
• Coordinate regular penetration tests, vulnerability triage, and cloud security posture management across GCP and Azure platforms
• Automate security tasks by contributing code to infrastructure and security tooling around our cloud platforms
• Foster secure practices by facilitating the Security Champions network, organizing security discussions, and delivering AI tooling safety training
• Share expertise, document processes, and mentor team members to build security capability across engineering
• Provide constructive feedback on Ki’s architecture and lead technical security discussions

The application process

• Initial recruiter screening call
• Interview with hiring manager
• Technical Interview (this may vary depending on the role)
• Values Interview

Benefits

• ⛱️ You'll get 27 days of holiday a year to start with—and if you’re craving a bit more downtime, you can top it up to 30 days by buying a few extra days off
• 🛐 Flexible Bank Holidays: Got a special cultural or religious day you want to celebrate? We've got your back with eight Cultural and Diversity days—you can use these instead of the usual UK bank holidays. It’s all about honouring what’s important to you
• 🏡 Flexible working: We’re all about flexibility! We’ve got a 50/50 hybrid approach—spend 2 to 3 days a week in our Leadenhall Building office in the heart of London, and work from home the rest of the time. It’s the best of both worlds!
• 🍼 For enhanced maternity leave, we offer up to 26 weeks of full pay. Shared parental and adoption leave is also available, ensuring you’re supported every step of the way as your family grows
• 💙 We’ve got your health covered with private medical insurance including pre-existing conditions, access to a virtual GP service and dental cover
• 🛡️ We’ve got you covered with income protection, giving you peace of mind if the unexpected ever happens
• 💰 Our non-contributory pension scheme means we invest in your future—no need for you to chip in!
• 🌿 Mental health: Our Employee Assistance Programme gives you access to a free, 24-hour confidential counselling service—there whenever you need a little extra support
• 📈 Through our ESOP, you’ll have the chance to invest in Fairfax, our parent company, and share in its growth
• ❣️ You can take up to 2 extra days off each year to volunteer with our amazing community partners—it’s a chance to give back and make a difference!
• 🎗️ We love supporting your charitable efforts! The company will match the money you personally raise for a registered charity, as long as you hit a minimum of £100
• 🪴 We’re serious about growth! Each department gets its own Learning & Development budget to help you level up your skills and thrive
• 🚃 Season ticket loan: Make your commute easier with an interest-free season ticket loan. The cost is covered upfront, and you’ll repay it in manageable instalments straight from your salary
• 🚲 Save money and stay active with our Cycle to Work scheme—making it easier to grab a bike and enjoy a greener commute!
• 🏆 We love celebrating wins! We have various ways to recognise and celebrate successes, shining a spotlight on all the remarkable things our teams achieve
• 🎉 We love bringing people together! From regular social events to team activities, there’s always something happening to foster connection and collaboration