Application Security Engineer

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.

Nice to Haves

• Experience building or owning authentication, SAML/SSO, identity, or access management capabilities.
• Experience securing AI-powered products or familiarity with security considerations for large language models, agentic systems, retrieval-based architectures, or AI tool integrations.
• Experience building security automation or security-focused platform capabilities at scale.
• Familiarity with cloud security, infrastructure security, or distributed systems.
• Experience working across both large-scale SaaS environments and high-growth companies.

What You'll Be Doing

• Own and engineer tier-zero security capabilities that help customers securely deploy and manage Fin.
• Design, build, and evolve customer-facing security features.
• Partner with engineering teams throughout the software development lifecycle.
• Perform architecture reviews, threat modelling exercises, and security assessments.
• Lead application security initiatives across the software development lifecycle.
• Participate in a shared on-call rotation and lead security incident response.
• Help shape Fin's AI-first approach to security.

Perks and Benefits

• Competitive salary and equity in a fast-growing start-up.
• Lunch provided every weekday, snack foods, and a fully stocked kitchen.
• Regular compensation reviews.
• Unlimited access to Claude Code and best-in-class AI tools.
• Pension scheme with a match up to 4%.
• Comprehensive health and dental insurance, life assurance.
• Flexible paid time off policy.
• Paid maternity leave and 6 weeks paternity leave.
• Cycle-to-Work Scheme and secure bike storage.
• Choice between MacBooks and Windows for certain roles.