Staff Machine Learning Engineer responsible for establishing ML standards and practices across AppFolio's Leasing Engineering team, from prompt engineering and RAG to fine-tuning and model selection. The role requires building and scaling production ML infrastructure with SaaS-grade reliability, owning SLOs, observability, and on-call posture for systems powering the Leasing Performer product.… The engineer will lead architectural discussions, guide technical decision-making, and ensure ML systems meet production discipline standards. Requires 7+ years of web-application development (preferably SaaS), hands-on experience training/fine-tuning language models end-to-end, expertise with RAG patterns and LangChain/LangGraph, and demonstrated AI safety and authorization implementation in production agentic systems.