Application Security Engineer
Build and operate customer-facing application security capabilities for a SaaS company, including identity, access control, security tooling, threat modeling, and incident response. The role partners closely with engineering teams and helps secure AI-powered products and development workflows.
About the job
Responsibilities
- Own and engineer tier-zero security capabilities that help 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 Fin's 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.
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.
- Comfort 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.
Compensation and Benefits
- Competitive salary and equity in a fast-growing start-up.
- Lunch served every weekday, snacks, and a fully stocked kitchen.
- Regular compensation reviews.
- Unlimited access to Claude Code and other AI tools.
- Pension scheme with matching up to 4%.
- Life assurance and comprehensive health and dental insurance for employees and dependents.
- Flexible paid time off policy.
- Paid maternity leave and six weeks of paternity leave.
- Cycle-to-Work Scheme and secure bike storage.
- MacBooks are standard, with Windows available for certain roles.
Skills
Application Security, Product Security, SaaS, Authentication, Saml/Sso, Authorization, Identity Management, Threat Modeling, Security Assessments, Incident Response, Security Automation, Cloud Security, Infrastructure Security, Distributed Systems, LLMs
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