Senior Software Engineer, Backend (Identity International)

About this role

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. 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, we’re excited to work with someone who leaves things better than they found them, communicates clearly across audiences, uses customer feedback to influence technical plans, and helps the team continuously improve.

This is a deeply technical, hands-on coding role where feature velocity and operational excellence go hand-in-hand. You’ll spend most of your week in the codebase - leveraging AI tools to write robust Kotlin and Python, ship impactful features, investigate complex production issues, and keep our systems rock-solid and reliable. This is a high-visibility, high-impact role for someone who wants to work on foundational systems that directly enable Affirm’s global growth.