Remote Senior Backend Engineer, AI Platform & Infra

Affirm, Inc.; Sioux Falls (SD); Remote; USD 173,000 - 233,000; Full time

Benefits offered by this job

Health coverage for you and dependents

Monthly tech stipends and wellness

Flexible time off and holidays

Employee stock purchase plan

Job summary

Affirm is hiring for a remote-first Backend Engineer to join the AI Platform team, shaping the gateway, runtime, and evaluation services that power AI workloads across millions of users.

The role focuses on designing robust, scalable backend systems, leading technical decisions, and partnering across security, infrastructure, and product teams. A strong emphasis on ownership, code quality, and mentorship is expected, with broad opportunities to impact production AI tooling and governance.

Qualifications

• 4+ years designing, developing and launching backend systems at scale.
• Experience with Python or Kotlin and scalable distributed systems.
• Experience with AWS, MySQL, and Kubernetes.
• Practical experience building with LLMs, agents, or AI frameworks in production.

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 identity, quota, routing, caching, and failover controls.
• Partner with security, infrastructure, and product engineering teams to set guardrails for agentic workloads and 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.
• Set and improve code review and design standards, and advocate for them beyond your team.
• Use AI tools and agentic workflows every day to multiply your own coding and design efforts.
• Educate, mentor, and grow engineers in the team.

Skills

Python

Kotlin

Distributed systems

Backend design

Education

Bachelor’s degree or equivalent

Tools

AWS

MySQL

Kubernetes

Job description

Affirm is hiring for a remote-first Backend Engineer to join the AI Platform team, shaping the gateway, runtime, and evaluation services that power AI workloads across millions of users.

The role focuses on designing robust, scalable backend systems, leading technical decisions, and partnering across security, infrastructure, and product teams. A strong emphasis on ownership, code quality, and mentorship is expected, with broad opportunities to impact production AI tooling and governance.