Staff CIAM Software Engineer

Affirm is reinventing credit to make it more honest and friendly. We're building the next generation of customer identity and authentication, and this role is a hands-on engineering position within Information Security focused on designing and shipping core CIAM capabilities that protect customers and support growth.

About the Role

You will design, build, and operate backend services that power registration, login, authorization, and account lifecycle flows across B2C and B2B experiences. Working closely with partner engineering teams, you'll ensure identity features are delivered with strong security fundamentals, reliability, and operational rigor.

Responsibilities

• Design, build, and operate core CIAM backend services supporting customer registration, authentication, authorization, account lifecycle, and profile management for B2C and B2B platforms.
• Implement and extend identity standards including OAuth 2.0, OIDC, SAML, and SCIM, ensuring correctness, scalability, and clean integration patterns.
• Develop backend APIs and services in Python and Kotlin that expose identity capabilities to web, mobile, and partner applications.
• Integrate CIAM platforms with internal systems, including user data stores, messaging, fraud signals, and downstream customer platforms.
• Own secure authentication and account flows end to end, including MFA, step-up authentication, device binding, consent, and adaptive authentication logic.
• Automate CIAM infrastructure and deployments using Infrastructure as Code and CI/CD pipelines, treating identity as a core platform service.
• Monitor, debug, and optimize CIAM services for performance, resilience, and abuse detection in high-scale environments.

Requirements

• 7+ years of professional experience designing, developing, and launching backend systems at scale using languages such as Python or Kotlin.
• Extensive track record developing highly available distributed systems using AWS, MySQL, Spark, and Kubernetes.
• 5+ years of hands-on experience designing and implementing CIAM systems with deep knowledge of OAuth 2.0, OIDC, SAML, and SCIM beyond basic configuration.
• Proven ability to deliver major features, system components, or deprecate existing functionality through clear technical and execution planning.
• Strong verbal and written communication skills supporting effective collaboration with global engineering teams.
• Track record writing high-quality code that is easily understood and used by others.