Remote Senior Backend Engineer, AI Platform & Gateway

Affirm, Inc.; San Diego (CA); Remote; USD 195,000 - 255,000; Full time

Job summary

Affirm’s AI Platform team builds scalable, secure infrastructure for AI workloads, gateways, and agent runtimes. We seek engineers who can own design decisions, ship production-grade backend systems, and advance AI tooling with strong collaboration across security and product teams.

We hire for distributed, high-availability systems expertise, modern cloud stacks, and a proactive mindset. This remote-first role offers strong growth and competitive compensation in the U.S. market.

Qualifications

• 4+ years designing, developing and launching backend systems at scale.
• Experience with AWS, MySQL and Kubernetes.
• Practical experience with LLMs, agents, or AI frameworks in production.
• Ability to design with elegant, simple, extensible architecture.
• Ownership of growth and proactivity in feedback.

Responsibilities

• Plan, execute, and own technical decisions and projects within the AI Platform team, from design through launch and on-call.
• Design and build gateway, runtime, and evaluation services handling AI workloads at scale.
• Implement identity, quota, routing, caching, and failover controls for model/tools adoption.
• Collaborate with security, infra, and product engineering to set guardrails for agent workloads.
• Create and monitor metrics; own operational health including monitoring, alerts, and on-call.
• Set and improve code review and design standards; advocate beyond the team.
• Use AI tools and agentic workflows to boost team delivery.
• Mentor engineers and promote best practices in design, coding, and testing.

Skills

Backend design

Python or Kotlin

Distributed systems

LLMs/AI frameworks

On-call experience

Education

Bachelor’s degree or equivalent

Tools

AWS

MySQL

Kubernetes

Job description

Affirm’s AI Platform team builds scalable, secure infrastructure for AI workloads, gateways, and agent runtimes. We seek engineers who can own design decisions, ship production-grade backend systems, and advance AI tooling with strong collaboration across security and product teams.

We hire for distributed, high-availability systems expertise, modern cloud stacks, and a proactive mindset. This remote-first role offers strong growth and competitive compensation in the U.S. market.