Staff ML Engineer — AI Infra & Cost Optimization

AppFolio; San Diego (CA); Hybrid; USD 200,000 - 275,000; Full time

Job summary

AppFolio is building Realm‑X, an AI-native platform that powers our next generation of real estate tech. We are hiring a Staff Machine Learning Engineer to own the ML platform lifecycle, from training and fine-tuning to inference and cost discipline.

You will partner with Voice & Agents and Research ML teams to harden prototypes into production systems, ensure observability, and implement guardrails while scaling Realm‑X across our customer base.

Qualifications

• 7+ years building and scaling web apps.
• Systems thinker with platform mindset.
• Production ML infra experience.
• Ability to operate in ambiguity.
• Owner-operator mindset and urgency.
• Strong collaboration and low ego.
• Focus on sustainability and work-life balance.
• Reliability mindset with SLOs/on-call.

Responsibilities

• Design and operate AppFolio's ML infrastructure on AWS (ECS, SageMaker, GPUs).
• Optimize AI costs across providers and models.
• Maintain reliable multi-provider LLM access (Google, OpenAI, Anthropic).
• Build training and fine-tuning stack for LLMs.
• Harden prototypes into production with SLOs and observability.
• Implement AI safety guardrails and tool permissions.

Skills

ML infrastructure

Production ML

Python

Docker

CI/CD

LangChain

LangGraph

AWS

Cost optimization

AI safety

Education

Bachelor's in CS

Master's in CS

PhD (optional)

Tools

SageMaker

Vertex AI

OpenAI API

Anthropic API

Job description

AppFolio is building Realm‑X, an AI-native platform that powers our next generation of real estate tech. We are hiring a Staff Machine Learning Engineer to own the ML platform lifecycle, from training and fine-tuning to inference and cost discipline.

You will partner with Voice & Agents and Research ML teams to harden prototypes into production systems, ensure observability, and implement guardrails while scaling Realm‑X across our customer base.