Senior CIAM Engineer

Affirm is reinventing credit to make it more honest and friendly, giving consumers the flexibility to buy now and pay later without any hidden fees or compounding interest.

Affirm values information security as a critical part of the company’s continued success. Our mission is to make information security programmatic and cultural in Affirm, enabling the company to succeed in building honest financial products. The Security team posture increases security and reduces risk while securely enabling access to information for those who need it!

The Senior CIAM Engineer candidate will have experience building and architecting software as part of a larger team. The ideal candidate will work effectively with product and engineering teams to evaluate and influence product requirements, design, and implementation to improve the security of Affirm’s products.

What you’ll do

• You have 5+ years of experience designing, developing and launching backend systems at scale using languages like Python or Kotlin.
• You have an extensive track record of developing highly available distributed systems using technologies like AWS, MySQL, Spark and Kubernetes.
• You have strong verbal and written communication skills that support effective collaboration with our global engineering team.
• You have experience delivering major features, system components or deprecating existing functionality in a system through the definition of a technical and execution plan. You write high quality code that is easily understood and used by others.
• Design, build, and operate core CIAM backend services that support customer registration, authentication, authorization, account lifecycle, and profile management for B2C and B2B platforms.
• Implement and extend identity standards such as OAuth 2.0, OIDC, SAML, and SCIM in code, 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 optimise CIAM services for performance, resilience, and abuse detection in high-scale environments.

What we look for

• Strong experience designing and implementing CIAM systems, with deep, hands-on knowledge of OAuth 2.0, OIDC, SAML, and SCIM beyond basic configuration.
• Proven backend engineering experience, with production proficiency in Python and Kotlin building APIs and distributed services.
• Hands-on experience extending and integrating CIAM platforms such as Okta, Auth0, Ping Identity, ForgeRock, or Azure AD B2C using custom code, hooks, and APIs.
• Solid understanding of backend and distributed systems fundamentals, including API design, data modeling, latency, error handling, and observability.
• Experience with Infrastructure as Code and automation tools such as Terraform, plus CI/CD pipelines for deploying backend services.
• Strong security fundamentals applied through engineering, including access control models, token handling, encryption, MFA, and privacy by design.
• Clear communication skills and the ability to work closely with product, frontend, mobile, and security teams while owning backend identity services.

Compensation & Benefits

Pay Grade - N

Equity Grade - 5

Employees new to Affirm typically come in at the start of the pay range. Affirm focuses on providing a simple and transparent pay structure which is based on a variety of factors, including location, experience and job-related skills.

Base pay is part of a total compensation package that may include monthly stipends for health, wellness and tech spending, and benefits (including 100% subsidised medical coverage, dental and vision for you and your dependents). In addition, the employees may be eligible for equity rewards offered by Affirm Holdings, Inc. (parent company).

Base pay range per year: £117,000 - £157,000

Location; UK Remote

Additional benefits include:
• Type of employment: Contract of Employment
• Flexible Spending Wallets for tech, food and lifestyle
• Away Days - wellness days to take off work and recharge
• Learning & Development programs
• Parental benefits
• Employee Resource & Community Groups
• This role is eligible for creative tax benefits, subject to applicable law and company policy

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