Senior Software Engineer, Backend

Affirm is a financial technology company that provides transparent, flexible payment options, with no hidden fees or surprises. We use advanced technology and analytics to serve a broader population than traditional lenders.

The Merchant & Partner Lifecycle (M&PL) team is at the forefront of Affirm's architectural transformation, consolidating merchant lifecycle orchestration into a cohesive domain. As a Senior Software Engineer, you will act as a technical leader building a new lifecycle-orchestrator service that is central to multiple connected systems. Your work will deliver immediate availability improvements through system simplification and isolation, and modernize older parts of the codebase.

• Design and expand the backbone of our platform to scale to hundreds of thousands of merchants worldwide.
• Design and align scope of work with other teams to deliver cross-team projects.
• Mentor other engineers to ensure their development and growth.
• Partner with Engineering Manager and Team Lead to drive and execute the long-term vision of the team.
• Execute technical strategy for broad or complex requirements with forward-looking approaches that solve large open-ended problems.
• Utilize agentic development tools like Claude Code to automate parts of the development process.
• Improve engineering standards, tooling, and processes throughout the organization.

• 5+ years of experience as a backend software engineer.
• Strong understanding of Domain-Driven Design, distributed systems, and how architectural decisions affect performance and maintainability.
• Proficiency with data models, API design (HTTP and RPC), state machines, event-driven architecture, and database design.
• Excellent written and verbal communication skills, including asynchronous communication—written tech specs, ADRs, project plans, etc.
• Experience designing, developing, and launching backend systems (our stack: AWS, gRPC, Snowflake, Kotlin, Python, MySQL, Kubernetes). Java and Kotlin experience are especially helpful.
• Prior experience with monitoring and alerting systems (sentry.io, rollbar, chronosphere, kibana).

Base pay is part of a total compensation package that may include equity rewards, monthly stipends for health, wellness and tech spending, and benefits (including 100% subsidized medical coverage, dental and vision for you and your dependents).

USA base pay range (CA, WA, NY, NJ, CT) per year: 195,000 - 255,000
USA base pay range (all other U.S. states) per year: 173,000 - 233,000

Benefits highlights: Health coverage at no cost (100% of premiums for employees and dependents), spending stipends, flexible time off and generous holiday calendars, and an employee stock purchase plan (ESPP) that lets you buy Affirm stock at a discount.

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