Application Security Engineer

The role

This role sits within Fin's Security Engineering group, a team that operates critical trust services and also builds security features customers use directly. The engineer works as a builder who partners with product teams to bake security into how software is designed and shipped, with an emphasis on AI-era threats.

What you would do

• Build and run the highest-criticality security services, including identity and login systems and audit trails
• Create customer-facing controls such as access management, permissions, and malicious link scanning
• Review designs, model threats, and run security assessments for new features
• Develop internal tooling and automation that makes secure coding the easy default
• Set and promote secure development guidance across the organization
• Lead application security work across the development lifecycle and head incident response and remediation
• Take part in an on-call rotation for security issues
• Assess and reduce risks introduced by AI-driven products and AI-assisted coding tools

What they asked for

• Hands-on background in application or product security within software-as-a-service products
• Solid software engineering background running production systems
• Working knowledge of modern app security threats, secure development, and threat modelling
• Experience with authentication, authorization, or enterprise identity controls
• Track record performing architecture reviews and security assessments
• Practical incident response experience, including leading investigations
• Strong coding ability and experience building internal tools or automation
• Comfort with AI-assisted development tools and clear cross-functional communication

Nice to have

• Experience building or running SSO, SAML, or identity and access management
• Experience securing AI or LLM-based products and agentic or retrieval systems
• Experience building security automation at scale
• Familiarity with cloud, infrastructure, or distributed systems security
• Exposure to both large SaaS platforms and fast-growing companies