Senior Backend Software Engineer

Role overview

Join Affirm as a Senior Backend Software Engineer and act as a technical leader building a new lifecycle-orchestrator service. You will modernize legacy components, scale the platform to support hundreds of thousands of merchants, and mentor other engineers while aligning scopes across teams.

Key missions

• Build and modernize the lifecycle-orchestrator service and improve older parts of the codebase.
• Scale the platform by expanding the core backend “backbone” to support very large merchant volumes.
• Mentor and raise engineering standards: improve tooling, processes, and execution of the team’s long-term vision.
• Collaborate across teams to align project scope and deliverables.

Requirements

• Strong understanding of Domain-Driven Design (DDD), distributed systems, and how architectural choices impact performance and maintainability.
• Experience with monitoring and alerting (e.g., Sentry, Rollbar, Chronosphere, Kibana).
• Excellent written and verbal communication, including asynchronous communication (tech specs, ADRs, project plans).
• 5+ years experience building and launching backend systems.

Preferred / helpful

• Experience designing with the stack listed, especially Java/Kotlin.
• Proficiency in:
  • Data modeling
  • API design (HTTP and RPC)
  • State machines
  • Event-driven architecture
  • Database design

Stack (provided)

• AWS, gRPC, Snowflake, Kotlin, Python, MySQL, Kubernetes