Senior Software Engineer, Backend (Payments)

About the Role

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. As a Senior Software Engineer on the Consumer Payments team, you'll own the design and delivery of backend systems powering Affirm's Payment Processing Network, which currently processes billions of dollars annually. You'll lead engineers through ambiguous, open-ended problems while collaborating across product, design, and analytics teams to drive feature development and international expansion.

About the Team

The Engineering team at Affirm builds reliable, performant, and scalable solutions across the platform. The Consumer Payments team focuses on payment processing infrastructure—systems vital to Affirm's core business. You'll work alongside partner teams across Europe and the US to support growth, improve key financial metrics, and maintain the high-throughput, high-availability systems the business depends on.

Responsibilities

• Own and deliver quarterly goals for your team, guiding engineers through complex, ambiguous problems to resolution
• Partner with product management, design, and analytics during ideation and decision-making, clearly articulating technical constraints and trade-offs
• Identify and advocate for solutions to project, process, technology, and business issues
• Support operational excellence by creating and monitoring metrics, escalating issues, and participating in on-call rotations
• Establish and improve code review and design standards, promoting quality and ownership across your team and beyond
• Develop talent on your team through feedback, guidance, and leadership by example

Requirements

• 4+ years designing, developing, and launching backend systems at scale using languages such as Python or Kotlin
• Proven track record building and operating high-throughput, high-availability payment or financial systems
• Experience leading and mentoring engineers

Benefits

• Remote role based in UK