Senior Software Engineer, Backend (Card)

Affirm is reinventing credit to make it more honest and friendly—offering consumers buy now, pay later flexibility without hidden fees or compounding interest. We're transforming credit cards through direct partnerships with card issuers, creating transparent payment solutions for everyday and large purchases. This Senior Software Engineer role focuses on the backend systems powering card transaction processing, ledgering, and reconciliation at scale.

About the Role

You'll lead backend engineering work across Affirm's card platform, spanning just-in-time transaction processing that executes in milliseconds and post-transaction ledgering and reconciliation systems. You'll own quarterly goals for your team, guide engineers through ambiguous problems, and collaborate across product, design, and analytics to build payment infrastructure that serves both everyday and large purchases.

Responsibilities

• Own and deliver quarterly goals for your team; lead engineers through ambiguity to solve open-ended problems
• Collaborate with product management, design, and analytics—participate in ideation, articulate technical constraints, and partner on decisions that weigh risks and trade-offs
• Identify and advocate for project, process, technology, or business issues; lead solutions
• Support operations and availability of team artifacts by creating and monitoring metrics, escalating when needed, and participating in on-call efforts
• Foster a culture of quality and ownership by setting or improving code review and design standards; advocate for them through writing and tech talks
• Develop talent on your team through feedback, guidance, and example

Requirements

• 4+ years of experience as a software engineer
• Proven experience designing, developing, and launching backend systems at scale using Python, Kotlin, AWS, MySQL, and Kubernetes
• Experience shipping front-end applications
• Demonstrated ability to define technical plans for significant features or system components with elegant, simple, and extensible design
• Ability to write high-quality code that is easily understood and used by others
• Proficiency making significant changes in large codebases safely, with developed tools and practices to enable your team

Location

Remote, Poland