Senior Software Engineer, Backend (Identity International)

Affirm is a financial technology company that provides a clear, predictable way to pay over time, with no hidden fees or surprises. The Identity team is mission-critical to the customer checkout experience, owning identity checks for all markets outside North America, including KYC, user lifecycle management, and identity decisioning across multiple regulatory environments. The team consists of six engineers based across Spain and Poland.

We are looking for a Senior Software Engineer to turn ambiguous business and customer problems into reliable, well-designed technical solutions. You will help shape quarterly technical direction, translate team goals into concrete projects, and identify cross-cutting risks and tradeoffs. You will take ownership beyond shipping code: raising code quality and review standards, making performance and scale tradeoffs explicit, and improving operational health. You will reduce toil, create playbooks, mentor engineers, support new hires and interns, and contribute to high-signal hiring. This is a deeply technical, hands-on coding role where you will spend most of your week in the codebase, leveraging AI tools to write robust Kotlin and Python, ship impactful features, investigate production issues, and keep systems reliable.

• Own and deliver quarterly goals for your team, leading engineers through ambiguity to solve open-ended problems.
• Collaborate with product management, design, and analytics in the product development lifecycle, articulating technical constraints and partnering on decisions that consider risks and tradeoffs.
• Proactively identify project, process, technology, or business issues, advocate for them, and lead in solving them.
• Support operations and availability of your team's artifacts by creating and monitoring metrics, escalating when needed, and supporting on-call efforts.
• Foster a culture of quality and ownership by setting or improving code review and design standards, and advocating for them through writing and tech talks.
• Help develop talent on your team by providing feedback and guidance, and leading by example.
• Participate in an on-call rotation as a requirement.

• 4+ years of experience designing, developing, and launching backend systems at scale using languages like Python or Kotlin.
• Track record of developing highly available distributed systems using technologies like AWS, MySQL, and Kubernetes.
• Experience defining a technical plan for delivery of a significant feature or system component with an elegant, simple, and extensible design.
• Ability to make significant changes in a large codebase safely, with a suite of tools and practices.
• Ownership of your growth, proactively seeking feedback from your team, manager, and stakeholders.
• Strong verbal and written communication skills for effective collaboration with a global engineering team.

Pay Grade: N, Equity Grade: 4. Base pay range per year: €86,000 - €122,000. Total compensation may include monthly stipends for health, wellness, and tech spending, and benefits including 100% subsidized medical coverage, dental, and vision for you and your dependents. Employees may be eligible for equity rewards offered by Affirm Holdings, Inc. Additional benefits include Flexible Spending Wallets for tech, food, and lifestyle, Away Days (wellness days), Learning & Development programs, Parental benefits, and Employee Resource & Community Groups.

Remote Spain. Visa sponsorship is available, but you must be based in Spain.