Backend Software Engineer (Merchant Advocacy)

Role Overview

Join Affirm as a Backend Software Engineer for the Merchant & Partner Lifecycle (M&PL) team. You will be a technical leader building a new lifecycle-orchestrator service, improving system availability, and modernizing legacy parts of the codebase.

Key Missions

• Lead technical delivery for the lifecycle-orchestrator service, including immediate availability improvements and modernization of older components.
• Design and expand the platform backbone to scale to hundreds of thousands of merchants, coordinating scope with other teams for cross-team initiatives.
• Execute technical strategy for broad/complex requirements, using agentic development tools to automate parts of the development process.

Responsibilities (What you’ll do)

• Build and evolve backend services and platform capabilities.
• Design APIs and data models and evolve system architecture for scale.
• Collaborate cross-team to align on long-term vision and deliverables.
• Improve reliability through observability practices and operational ownership.

Requirements

• Experience with data models, API design (HTTP and RPC), state machines, event-driven architecture, and database design.
• 3+ years of backend software engineering experience (or equivalent practical experience).
• Experience designing, developing, and launching backend systems.
• Strong communication skills, including proficiency with written async communication (tech specs, ADRs, project plans).

Nice-to-Haves / Preferred

• Familiarity with Domain-Driven Design (DDD) and distributed systems.
• Experience with the stack: AWS, gRPC, Snowflake, Kotlin, Python, MySQL, Kubernetes (Java/Kotlin especially helpful).
• Experience with monitoring and alerting (e.g., Sentry, Rollbar, Chronosphere, Kibana).