Senior AI Platform Backend Engineer (Remote)

Affirm, Inc.; Boston (MA); Remote; USD 173,000 - 233,000; Full time

Benefits offered by this job

Health coverage 100% for employees and

Monthly tech stipends

Job summary

Affim is seeking a backend engineer to design, build and scale AI platform components for production workloads. You will own design decisions, implement gateways and runtimes, and govern AI tool usage across millions of transactions.

You will collaborate with security and infra teams, define guardrails, and mentor engineers while delivering high-quality, observable systems with strong documentation.

Qualifications

• 4+ years designing, developing and launching backend systems at scale.
• Experience with AWS, MySQL and Kubernetes.
• Production experience with LLMs, agents or AI frameworks.
• Ability to plan a technical delivery with elegant design.
• Strong code and collaboration skills.

Responsibilities

• Plan, execute, and own technical decisions and projects within the AI Platform team.
• Design and build gateway, runtime, and evaluation services for AI workloads.
• Make AI spend attributable and governable with identity and quota controls.
• Partner with security and product teams to set guardrails for agent workloads.
• Create and monitor metrics and own operational health of systems.
• Set code review standards and advocate them across the team.
• Mentor engineers and drive best practices in design and testing.
• Use AI tools daily to improve development and operations.

Skills

Python

Kotlin

Distributed systems

AWS

MySQL

Kubernetes

LLMs/AI frameworks

Education

Bachelor’s degree in a related field

Equivalent practical experience

Tools

LiteLLM

MCP

tool calling

evals

agent runtimes

Job description

Affim is seeking a backend engineer to design, build and scale AI platform components for production workloads. You will own design decisions, implement gateways and runtimes, and govern AI tool usage across millions of transactions.

You will collaborate with security and infra teams, define guardrails, and mentor engineers while delivering high-quality, observable systems with strong documentation.