Senior Software Engineer, Backend Merchant Advocacy

Affirm is reinventing credit to make it more honest and friendly, giving consumers the flexibility to buy now and pay later without any hidden fees or compounding interest.

The Merchant & Partner Lifecycle (M&PL) team is at the forefront of Affirm’s architectural transformation. We are addressing critical architectural risks by consolidating merchant lifecycle orchestration into a newly cohesive domain.

You will act as a technical leader responsible for building out the brand new lifecycle-orchestrator service that’s at the heart of multiple connected systems. Your work will deliver immediate availability improvements through system simplification and isolation, and modernize older parts of the codebase.

What You'll Do

• Design & expand the backbone of our platform to scale to hundreds of thousands of merchants from all around the world
• Design and align the scope of work with other teams to deliver cross-team projects
• Mentor other engineers to ensure their development & 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 insightful and forward-looking approaches that go beyond the direct team and 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

What We Look For

• 5+ years of experience as a backend software engineer
• A 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 communication skills, both written and verbal. Must be proficient in 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)

Pay Grade - N Equity Grade - 8 Employees new to Affirm typically come in at the start of the pay range. Affirm focuses on providing a simple and transparent pay structure which is based on a variety of factors, including location, experience and job-related skills. 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: $190,000 - 240,000

USA base pay range (all other U.S. states)