Machine Learning Engineer

Overview

Build and operate the ML platform that powers App Folio’s AI-native Real Estate platform, ensuring scalable training, inference, and cost‑efficient operations across AWS and multi‑provider LLMs.

• Design and operate App Folio's ML infrastructure on AWS, including ECS, Sage Maker, GPU fleets, model serving, autoscaling, and cost controls.
• Optimize AI cost across all applications through routing, caching, batch vs. real‑time processing, model size selection, and inference economics.
• Maintain reliable multi‑provider LLM access across Google, OpenAI, and Anthropic, with fallbacks and abstractions.
• Build the training and fine‑tuning stack for small language models, including data pipelines, GPU orchestration, and evaluation.
• Productionize research prototypes with SLOs, on‑call rotations, and observability.
• Operate App Folio's AI safety and authorization layer, including guardrails on AWS, scoped tool permissions, and human‑in‑the‑loop gates.

• Experience building and operating production ML infrastructure at scale on AWS (ECS, Sage Maker, GPUs, autoscaling, cost controls).
• Production experience with model serving for LLMs and custom models, understanding quantization, batching, and routing.
• Direct experience integrating with Google Vertex/Gemini, OpenAI, and Anthropic APIs in production.
• Strong Python, Docker, dependency management, and CI/CD for AI workloads.
• Experience with RAG and agents (Lang Chain, Lang Graph, modern RAG patterns).
• Demonstrated cost optimization for AI workloads without regressing quality or latency.
• Hands‑on experience operating AI guardrails, scoped tool permissions, and authorization layers.
• Systems thinker, production builder, owner‑operator, strong desire to move fast, collaborative, and reliable mindset.

• Experience training small language models for production use.
• GPU performance tuning (vLLM, TensorRT, Triton, or similar).
• Prior staff‑level role in a company with a significant AI infra footprint.
• Experience with ontology‑driven systems or knowledge graphs supporting AI applications.
• Contributions to open‑source ML infrastructure or LLM tooling.

Remote (San Francisco, CA; Denver, CO; Santa Barbara, CA; San Diego, CA)

Base salary $200,000 – $250,000 per year. Total rewards include benefits and potential discretionary bonuses.

At App Folio, we value diversity in backgrounds and perspectives and depend on it to drive our culture. App Folio is a proud Equal Opportunity Employer, and we welcome individuals of any race, color, religion, sex, sexual orientation, gender identity, national origin, age, marital status, ancestry, physical or mental disability, or veteran status.