Staff Software Engineer, Backend (Card)

Affirm is reimagining consumer credit through buy-now-pay-later solutions and next-generation card products. As Staff Software Engineer for our Cards team, you'll lead backend architecture and engineering strategy for EU operations, overseeing transaction processing systems that execute in milliseconds alongside post-transaction ledgering and reconciliation infrastructure.

About the Role

You will serve as the lead engineer for all card-related backend systems across our EU teams, based in Spain. This role bridges technical leadership and hands-on development, requiring you to set year-long technical strategy while collaborating across product, design, and analytics. You'll work on payment infrastructure spanning real-time transaction processing and financial reconciliation systems, and you'll be responsible for team operations, on-call rotations, and incident response.

Responsibilities

• Define and communicate technical strategy for your team on a 12-month horizon, aligning with business-critical initiatives
• Lead all backend engineering for EU card products, making architectural decisions across payment processing and ledgering systems
• Collaborate with product, design, and analytics teams to evaluate technical trade-offs, risks, and sustainability considerations
• Establish operational excellence through monitoring, alerting, triage processes, and on-call playbooks to ensure system reliability
• Set code review standards and design practices for your team; advocate for quality through documentation and technical talks
• Develop team members through mentoring, feedback, and leading by example
• Participate in on-call rotation for incident response and operational support

Requirements

• 8+ years of software engineering experience
• Proven expertise designing and scaling backend systems with Python, Kotlin, AWS, MySQL, and Kubernetes
• Experience shipping major features, system components, or deprecations with clear technical and execution planning
• Ability to write maintainable, well-documented code that others can easily understand and extend
• Comfort navigating ambiguity and working across abstraction levels, from language-level details to system architecture
• Front-end development experience

Benefits

Remote position based in Spain with access to a global team spanning EU locations including Poland.