Founding Security Engineer

About this role

Casca seeks a Founding Security Engineer to build security infrastructure for an AI-native banking platform handling sensitive borrower data. You'll own application security, threat modeling, AI attack surface defense, and incident response while shipping production code that scales security across a fast-growing fintech startup.

What you'll do

• Design and implement security detections, libraries, and policy-as-code deployed as production services
• Conduct threat modeling and design reviews for authentication, tenant isolation, data handling, and PII protection
• Secure the AI attack surface including prompt injection, tool-use abuse, and agent exfiltration paths with evals
• Lead incident response end-to-end and translate findings into system hardening
• Convert bank security audits and compliance reviews into engineering improvements
• Communicate security risk to engineers and collaborate on shipped fixes

What they're looking for

• Application security with documented experience finding bugs and hardening systems
• Production coding in TypeScript/Node.js and Python
• Multi-tenant system authorization and security boundary design
• LLM and agentic product security (preferred)
• Regulated financial systems compliance (SOC 2, GLBA, FFIEC)
• Incident response and post-incident analysis
• Security tooling and CI/CD integration
• Third-party risk assessment and audit support

Benefits

• Equity in a fast-growing AI fintech startup
• End-to-end ownership of security initiatives with direct business impact
• Collaborative team environment with mentorship and professional growth
• Opportunity to shape AI security in regulated banking
• High-intensity, high-impact work at the frontier of fintech innovation