Senior Software Engineer, Backend (Merchant Advocacy)

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.

• →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

• 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)