Senior Backend Engineer, AI Platform – Remote

Affirm, Inc.; Salt Lake City (UT); Remote; USD 173,000 - 255,000; Full time

Benefits offered by this job

100% medical premiums for you and your

Dependent coverage

Spending stipends for hardware/health

Flexible time off

Employee stock purchase plan (ESPP)

Job summary

Affirm, Inc. is seeking an experienced backend engineer to own design, development, and productionization of AI Platform components.

You will build gateways, runtimes, and evaluation services that scale AI workloads for millions of users, and establish guardrails for secure, governable model and tool access. You will collaborate across security, infra, and product teams, defining technical plans for large features and driving high-quality, maintainable code.

Qualifications

• 4+ years designing, developing and launching backend systems at scale with Python or Kotlin
• Experience building highly available distributed systems with AWS, MySQL and Kubernetes
• Hands-on experience with AI workloads: LLMs, agents, or AI frameworks in production
• Ability to define a technical plan for delivering a significant feature or system component
• Proven ability to write high quality, maintainable code and evolve systems safely
• Demonstrated ownership of growth, feedback, and collaboration with stakeholders

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 to scale AI workloads across millions of users
• Implement identity, quota, routing, caching, and failover controls for model and tool access
• Partner with security, infrastructure, and product teams to set guardrails for agentic workloads
• Create and monitor metrics, maintain operational health, runbooks, alerts, and on-call readiness
• Set and improve code review and design standards and advocate them beyond the team
• Use AI tools and agentic workflows to multiply code, reviews, and operations
• Educate, mentor, and grow engineers, promoting best practices in design, coding, and testing

Job description

Affirm, Inc. is seeking an experienced backend engineer to own design, development, and productionization of AI Platform components.

You will build gateways, runtimes, and evaluation services that scale AI workloads for millions of users, and establish guardrails for secure, governable model and tool access. You will collaborate across security, infra, and product teams, defining technical plans for large features and driving high-quality, maintainable code.