Senior Software Engineer, Backend (Card Acquisition)

Affirm is reinventing credit to make it more honest and friendly, giving consumers the flexibility to buy now and pay later without hidden fees or compounding interest. We're seeking a Senior Software Engineer to join our Card Acquisition team, where you'll own the technical strategy and execution for the first experience customers have with Affirm. In this role, you'll mentor engineers, drive operational excellence, and partner across product and design to build performant systems that directly impact conversion and retention.

About the Role

As a Senior Backend Engineer on the Card Acquisition team, you'll operate at the intersection of product, design, and engineering. You'll be responsible for defining long-term technical direction, leading senior engineers through ambiguous problems, and serving as a force multiplier through deep technical expertise and operational excellence. This is a remote position based in Spain and includes on-call rotation responsibilities.

Responsibilities

• Own and deliver quarterly goals for your team, guiding engineers through open-ended problems and ensuring support throughout delivery
• Collaborate with product management, design, and analytics to articulate technical constraints, assess trade-offs, and inform product decisions
• Proactively identify and lead resolution of project, process, technology, and business issues
• Establish monitoring, triage rotations, playbooks, testing, and alerting to support operational reliability and on-call efforts
• Set and advocate for code review and design standards across your team and the broader organization
• Develop talent through feedback, guidance, and technical mentorship
• Participate in on-call rotation for production support

Requirements

• 4+ years designing, developing, and launching backend systems at scale using Python, Kotlin, or similar languages
• Proven track record building highly available distributed systems using AWS, MySQL, Kubernetes, or equivalent technologies
• Experience defining technical plans for significant features or system components with elegant, simple, and extensible design
• Ability to write high-quality, maintainable code and make large-scale changes within complex codebases
• Strong communication and cross-functional collaboration skills

Benefits

Affirm offers competitive compensation, health benefits, and professional development opportunities for remote employees in Spain.