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. The Identity team is mission-critical to our checkout experience and international expansion. We're looking for a Senior Software Engineer to own identity decisioning, KYC, and user lifecycle management across multiple regulatory environments outside North America.

About the Role

You'll join a six-person team based across Spain and Poland, working on foundational identity infrastructure that directly impacts conversion, fraud exposure, and regulatory compliance. This is a hands-on coding role where you'll spend most of your time in the codebase—shipping features, investigating production issues, and maintaining system reliability. You'll help shape quarterly technical direction, translate business problems into well-designed solutions, and drive collaboration across team boundaries.

Responsibilities

• Own and deliver quarterly goals for your team, leading engineers through ambiguity on open-ended problems
• Design solutions across system boundaries and identify cross-cutting risks, tradeoffs, and opportunities
• Write robust production code in Kotlin and Python; leverage AI tools to improve development velocity
• Investigate complex production issues and maintain high availability and performance standards
• Collaborate with product management, design, and analytics on the product development lifecycle
• Reduce operational toil, create and maintain runbooks, and improve system observability
• Mentor engineers, support new hires and interns, and contribute to hiring efforts
• Advocate for technical investments that improve long-term execution and code quality

Requirements

• Strong backend software engineering experience with proven ability to own complex systems
• Proficiency in Kotlin, Python, or similar languages
• Experience designing systems that operate across regulatory or compliance boundaries
• Track record of mentoring engineers and supporting team growth
• Comfort with ambiguity and ability to turn vague business problems into concrete technical solutions
• Experience shipping features in a high-velocity environment without sacrificing reliability

Benefits

• Remote position based in Poland