Casca - Senior Security Engineer

Location: San Francisco, CA (On-site, 5 days in-office)
Salary: $190K–$250K base + competitive equity (higher for exceptional candidates)
Visa: Open to visa transfers (e.g. OPT, H1B transfers)

About this role

We are looking for a Founding Security Lead with 4-8 years of experience to own and evolve the application security program at a fast-growing AI-native fintech startup. You'll be a "super IC" – someone who thrives doing hands-on security work while naturally growing into technical leadership. This role is ideal for someone with a strong application security background who is passionate about securing AI agents and agentic workflows in a highly regulated banking environment. You'll join an existing security foundation and take it to the next level as the company scales from Series A through its next phase of growth.

What you will be doing

• Owning and maturing the application security program – building security tooling, processes, and secure SDLC practices that integrate naturally into how engineers ship code

• Securing the AI agent execution surface – partnering with engineering to establish robust security architecture for agentic workflows, ensuring data privacy and mitigating AI-specific vulnerabilities

• Driving automation of security processes – building detection pipelines, automating vulnerability management, and reducing manual security overhea