Senior Software Engineer, Backend (Identity International)

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’s Identity team is mission-critical to the customer checkout experience. When a customer chooses Affirm, one of the first steps is an identity check, and our ability to make the right decision directly impacts conversion, revenue, fraud exposure, and regulatory compliance. Our team owns Identity for all markets outside North America, playing a key role in Affirm’s international expansion. We are responsible for KYC, user lifecycle management, and identity decisioning across multiple regulatory environments. This work is about shaping how Affirm adapts its core Identity platform to new market dynamics, customer expectations, and compliance requirements. We are a team of six engineers based across Spain and Poland. We are looking for a Senior Software Engineer who can turn ambiguous business and customer problems into reliable, well-designed technical solutions. In this role, you will help shape our quarterly technical direction, translate team goals into concrete projects, and identify cross-cutting risks, tradeoffs, and opportunities. You should be comfortable designing across system boundaries, driving collaboration with partner teams, and advocating for technical investments that improve long-term execution. We’re looking for someone who takes ownership beyond shipping code: raising code quality and review standards, making performance, availability, and scale tradeoffs explicit, and improving the operational health of the systems they own. You’ll help reduce toil, create useful playbooks, mentor engineers, support new hires and interns, and contribute to high-signal hiring. Most importantly…