Senior Backend Engineer - AI Platform (Remote-First)

Affirm, Inc.; Pittsburgh (Allegheny County); Remote; USD 173,000 - 255,000; Full time

Benefits offered by this job

100% medical coverage for you and your

Dependent coverage

Tech setup stipends

ESPP

Job summary

Affirm, Inc. is hiring an experienced backend engineer to design, build, and scale AI platform infrastructure.

You will own technical decisions from design through on-call, and help shape gateways, runtimes, and evaluation services for millions of users. You will code in Python or Kotlin, build highly available distributed systems with AWS and Kubernetes, and collaborate with security and product teams to set guardrails for AI workloads.

Qualifications

• 4+ years designing, developing and launching backend systems at scale using languages like Python or Kotlin.
• Proven experience with highly available distributed systems (AWS, MySQL, Kubernetes).
• Hands-on with LLMs, agents, or AI frameworks in production: APIs, gateways, tool calling.
• Understanding AI usage and supporting AI workloads across disciplines.
• Technical plan for delivering significant features with simple, extensible design.
• High-quality, readable code that others can use.
• Ownership of growth and seeking feedback from team and stakeholders.
• Strong verbal and written communication for global collaboration.
• Equivalent practical experience or Bachelor's degree required.

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 scaling across millions of users.
• Make AI spend attributable and governable: identity, quota, routing, caching, and failover controls.
• Partner with security, infrastructure, and product teams to set guardrails for agent workloads and identity model access.
• Create and monitor metrics; own operational health, monitoring, runbooks, and on-call.
• Set and improve code review and design standards; advocate beyond your team.
• Use AI tools and agentic workflows daily to boost your own work and team delivery.
• Educate, mentor, and grow engineers; promote best practices.

Skills

Backend design

Distributed systems

Python/Kotlin

LLMs/AI frameworks

Technical planning

Code quality

Ownership

Communication

Education

Bachelor's degree or equivalent

Tools

AWS

MySQL

Kubernetes

Job description

Affirm, Inc. is hiring an experienced backend engineer to design, build, and scale AI platform infrastructure.

You will own technical decisions from design through on-call, and help shape gateways, runtimes, and evaluation services for millions of users. You will code in Python or Kotlin, build highly available distributed systems with AWS and Kubernetes, and collaborate with security and product teams to set guardrails for AI workloads.