Senior Software Engineer, Fullstack (Card Acquisition)

Affirm is reinventing credit to make it more honest and friendly, offering consumers the flexibility to buy now and pay later without hidden fees or compounding interest. We're seeking a Senior Full Stack Software Engineer to join the Acquisition & Onboarding team and lead technical strategy across our consumer-facing platforms. This leadership role combines hands-on engineering with mentorship, architectural ownership, and the opportunity to directly shape how millions of customers first experience Affirm.

About the Role

As a Senior Full Stack Software Engineer on the Acquisition & Onboarding team, you'll own the technical direction and delivery of systems that drive customer acquisition and initial onboarding experiences. You'll work across mobile (React Native and native), web, and backend to build performant, accessible interfaces that drive conversion and retention. This is a high-leverage position where you'll set standards for code quality, system reliability, and operational excellence while mentoring senior engineers and navigating complex cross-functional challenges.

Responsibilities

• Define and execute quarterly technical goals for your team, providing clear direction through ambiguous problems and ensuring successful delivery
• Lead architectural decisions and technical strategy across mobile, web, and backend systems; establish patterns and standards that elevate engineering quality across the team
• Collaborate with product, design, and analytics to scope features, articulate technical constraints, and advocate for solutions that balance risks and trade-offs
• Own team operations and on-call responsibilities by establishing monitoring, alerting, triage processes, runbooks, and testing protocols that ensure system reliability
• Identify and drive resolution of project, process, technology, and business challenges; escalate blockers and champion improvements
• Mentor and develop senior engineers on your team through feedback, guidance, and technical leadership by example
• Foster quality standards by defining code review practices, design standards, and best practices; evangelize these through technical documentation and team discussions

Requirements

• Proven experience leading significant mobile initiatives using React Native or native technologies, including architecture definition and cross-functional coordination
• Strong full stack expertise spanning mobile, web, and backend development
• Demonstrated ability to mentor and develop other senior engineers
• Track record of defining technical strategy and making sound architectural decisions
• Experience with on-call rotations, system monitoring, and operational excellence practices
• Ability to navigate ambiguity, communicate clearly across functions, and balance technical depth with business impact