Senior Software Engineer, Backend (AI Platform)

Responsibilities

• Plan, execute, and own technical decisions and projects within the AI Platform team, from design through launch and on-call.
• Design and build the gateway, runtime, and evaluation services that take AI workloads at Affirm from pilot to production, securely scaling across millions of users and their transactions.
• Make AI spend attributable and governable: build the identity, quota, routing, caching, and failover controls that let teams adopt new models and tools without re-solving the same platform problems.
• Partner with security, infrastructure, and product engineering teams to set the guardrails for agentic workloads and the on-behalf-of identity model for tool access.
• Create and monitor metrics for your team's systems, and own the operational health of what you ship: monitoring, alerting, runbooks, and on-call.
• Set and improve code review and design standards, and advocate for them beyond your team through writing and tech talks.
• Use AI tools and agentic workflows every day as a multiplier for your own code, design review, and operations, and push the team on what a small AI-native team can deliver.
• Educate, mentor, and grow engineers in the team, and drive best practices around design, coding, and testing.
• What We Look For
• You have 4+ years of experience designing, developing and launching backend systems at scale using languages like Python or Kotlin.

Languages