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 is building the next generation of customer identity and authentication. This role is a hands-on engineering position inside Information Security, focused on designing and shipping core CIAM capabilities that protect customers and support growth.

You will build and operate backend services that power registration, login, authorization, and account lifecycle flows across B2C and B2B experiences. You will work closely with partner engineering teams and ensure identity features are delivered with solid security fundamentals, reliability, and operational rigor. You have 7+ 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.



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. Strong experience designing and implementing CIAM systems, with deep, hands-on knowledge of OAuth 2.0, OIDC, SAML, and SCIM beyond basic configuration. 5+ years of professional backend software engineering experience Strong production experience in Python or a similar backend language Hands-on experience building and maintaining CI/CD pipelines Experience with cloud-native development, preferably AWS 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.

Familiarity with tools such as Cursor and other AI-augmented development environments Equity Grade - USA 7 Base pay is part of a total compensation package that may include equity rewards, monthly stipends for health, wellness and tech spending, and benefits (including 100% subsidized medical coverage, dental and vision for you and your dependents.) Affirm is proud to be a remote-first company! The majority of our roles are remote and you can work almost anywhere within the country of employment. Affimers in proximal roles have the flexibility to work remotely, but will occasionally be required to work out of their assigned Affim office.

A limited number of roles remain office-based due to the nature of their job responsibilities. Health care coverage - affirm covers all premiums for all levels of coverage for you and your dependents Flexible Spending Wallets - generous stipends for spending on Technology, Food, various Lifestyle needs, and family forming expenses Time off - competitive vacation and holiday schedules allowing you to take time off to rest and recharge We believe It's On Us to provide an inclusive interview experience for all, including people with disabilities.

📌 Staff CIAM Security Engineer (Montreal)
🏢 Affirm
📍 Montreal