Senior AI Security Engineer – Product & Threat Modeling

Affirm; San Diego (CA); On-site; USD 230,000 - 290,000; Full time

Benefits offered by this job

Health coverage

Equity

Wellness stipend

ESPP

Job summary

Affirm is seeking an experienced security engineer to build and run the end-to-end security review process for enterprise AI/LLM systems. You will evaluate architecture, data flows, and tool designs, embedding security requirements into design phases and driving risk remediation across Security, Legal, Privacy, Compliance, IT, and Engineering.

You will lead threat modeling and risk-based decisions for AI services, review code and configurations, and help create test cases and incident response

Qualifications

• Seasoned security engineer with hands-on experience in designing and maintaining security architecture for AI/LLM-based systems.
• Experience threat modeling and reviewing AI/LLM apps and securing agentic systems and tool-calling frameworks.
• Ability to build security tooling, guardrails, and detections with Python or similar, and deploy infrastructure as code (Terraform or similar).
• Familiarity with Kubernetes and AWS; knowledge of OAuth2, SAML, and non-human identities.

Responsibilities

• Lead and advance Affirm’s enterprise AI security review process across architecture, data flows, permissions, and design of internal AI tools and MCP-based systems.
• Threat model AI/LLM systems and data flows to identify risks and drive remediation.
• Review source code, prompts, agent configurations, and tool manifests; help owners build security-focused tests and red-team scenarios.
• Design and implement security guardrails and tooling for AI systems, including authz, data handling controls, logging, and policy-as-code.
• Evaluate third-party SaaS AI capabilities as part of vendor security reviews and guide risk-based adoption.
• Identify emerging AI/agentic vulnerabilities and contribute to incident response playbooks as a senior escalation point.
• Lead cross-functional AI security initiatives and communicate security posture to technical and executive stakeholders.

Skills

Security engineering

Threat modeling

AI/LLM security

Python

Infrastructure as Code

Kubernetes

AWS

OAuth2,SAML

Non-human identities

Tools

Notion AI

Slack AI

Google Workspace AI

GitHub Copilot

CASB

IdP/Okta

Job description

Affirm is seeking an experienced security engineer to build and run the end-to-end security review process for enterprise AI/LLM systems. You will evaluate architecture, data flows, and tool designs, embedding security requirements into design phases and driving risk remediation across Security, Legal, Privacy, Compliance, IT, and Engineering.

You will lead threat modeling and risk-based decisions for AI services, review code and configurations, and help create test cases and incident response