Application Security Engineer

Salary: £62,000 - 102,000 per year

Requirements:

• Proven application security, product security, or security engineering experience within a SaaS environment.
• Strong software engineering skills with experience designing, building, and operating production systems.
• Deep understanding of modern application security threats, secure software development practices, and threat modelling.
• Experience designing, building, or securing authentication, authorization, identity, or enterprise security capabilities.
• Experience conducting architecture reviews and security assessments for complex systems.
• Hands-on security incident response experience, including leading investigations and remediation efforts.
• Strong programming skills and experience building tools, automation, or developer-focused solutions.
• Comfortable using modern AI-assisted development tools to improve productivity and engineering effectiveness.
• Ability to communicate security concepts clearly and collaborate effectively with engineering teams.
• A pragmatic approach to balancing security, customer impact, and engineering velocity.
• Bonus: Experience building or owning authentication, SAML/SSO, identity, or access management capabilities.
• Bonus: Experience securing AI-powered products or familiarity with security considerations for large language models, agentic systems, retrieval-based architectures, or AI tool integrations.
• Bonus: Experience building security automation or security-focused platform capabilities at scale.
• Bonus: Familiarity with cloud security, infrastructure security, or distributed systems.
• Bonus: Experience working across both large-scale SaaS environments and high-growth companies.

Responsibilities:

• Own and engineer tier-zero security capabilities that help our customers securely deploy and manage Fin.
• Design, build, and evolve customer-facing security features, including authentication, SAML/SSO, permissions systems, audit and activity logging, malicious URL scanning, and other enterprise security controls.
• Partner with engineering teams throughout the software development lifecycle to build secure products and services.
• Perform architecture reviews, threat modelling exercises, and security assessments for new features and systems.
• Build security tooling, automation, and developer-facing building blocks that make secure development easier and more scalable.
• Contribute to secure development standards, guidance, and best practices across Fin.
• Lead application security initiatives across the software development lifecycle, helping teams identify and address security risks early.
• Participate in a shared on-call rotation and lead security incident response, investigation, and remediation efforts.
• Drive security initiatives from problem definition through design, implementation, and measurable outcomes.
• Partner with teams building AI-powered products to assess and mitigate emerging security risks.
• Help shape our AI-first approach to security, including AI-powered detection, red-team automation, continuous monitoring, and emerging defensive capabilities.
• Support the secure adoption of AI-assisted software development tools and engineering workflows.

Technologies:

• AI
• Claude Code
• Cloud
• Support
• SAML
• Security
• Windows

More:

We are Fin, the AI Customer Agent company on a mission to help businesses provide perfect customer experiences. Our AI Agent Fin is the highest-performing AI Customer Agent on the market, helping businesses deliver always-on support across service, sales, and ecommerce. Founded in 2011, we are one of the fastest growing companies and among the largest private software companies in the world, with nearly 30,000 global businesses using our products. Our Security Engineering team owns critical security services and customer-facing trust features, and we take an AI-first approach to security. We offer a hybrid working policy with at least three days per week in the office, competitive salary and equity, weekday lunch, snacks, a stocked kitchen, regular compensation reviews, unlimited access to Claude Code and best-in-class AI tools, pension matching up to 4%, health and dental insurance, life assurance, flexible paid time off, parental leave, and a Cycle-to-Work Scheme.

last updated 34 week of 2026