Application Security Engineer

About the role

Fin is seeking an engineer to join our security team to help build and maintain trusted AI-powered customer service tools. You will own tier-zero security services and partner with product teams to integrate security directly into our development lifecycle. This role focuses on designing secure systems, automating defenses, and protecting our global customer base.

Key facts

What you'll do

• Engineer and maintain tier-zero security services including authentication, SAML/SSO, audit logs, and malicious URL scanning.
• Conduct architecture reviews, threat modeling, and security assessments for new product features.
• Develop security tooling and automation to support scalable, secure software development.
• Lead security incident response, investigation, and remediation efforts as part of a shared on-call rotation.
• Collaborate with engineering teams to assess risks in AI-powered products and agentic systems.
• Establish secure development standards and provide guidance across the organization.
• Support the adoption of AI-assisted development tools and workflows.

Requirements

• Proven experience in application security, product security, or security engineering within a SaaS environment.
• Strong software engineering background with experience building and operating production systems.
• Deep knowledge of modern application security threats, secure coding practices, and threat modeling.
• Experience designing or securing identity, authorization, and enterprise security systems.
• Hands-on experience leading security incident response and investigations.
• Proficiency in programming and building developer-focused security tools.
• Ability to communicate complex security concepts to engineering teams and balance security with development velocity.

Nice to have

• Experience owning authentication, SAML/SSO, or access management systems.
• Background in securing AI-powered products, including large language models, retrieval-based architectures, or agentic systems.
• Experience building security automation at scale.
• Familiarity with cloud security, infrastructure security, or distributed systems.
• Experience working in both high-growth companies and large-scale SaaS environments.

Skills & tools

• Application Security
• Product Security
• Threat Modeling
• Authentication and Identity Management (SAML/SSO)
• Security Automation
• Incident Response
• AI-assisted development tools

Practical notes

• Compensation includes a competitive salary and equity with regular performance reviews.
• Benefits include health and dental insurance for employees and dependents, life assurance, and a pension scheme with up to 4% match.
• Perks include daily catered lunches, a fully stocked kitchen, flexible paid time off, and a Cycle-to-Work scheme.
• Parental leave includes paid maternity leave and 6 weeks of paternity leave.
• Hardware provided is typically a MacBook, though Windows options are available for specific roles.
• The company maintains a neutral policy on social and political topics to foster a focused work environment.