Principal Machine Learning Engineer

App Folio is more than a company. We’re a community of dreamers, big thinkers, problem solvers, active listeners, and multipliers. At every opportunity, we set the pace while delivering innovation built to carry real estate into the future. One in which every experience feels effortless, yet meaningful. Where customers are empowered to take on any opportunity. We show up as one team, connected by our values to be a force for good.

Because together, we have the power to create extraordinary outcomes for our customers, our communities, and ourselves.

Realm-X is App Folio's AI-native platform powering this transformation. It enables a new generation of intelligent capabilities across our products, including Realm-X Assistant (copilot), Flows (AI Agentic workflows) and Performers (autonomous AI Agents). Realm-X serves as both a foundation for internal teams to build and scale AI-powered products
, and a core layer delivering intelligent, high-impact experiences directly to our customers
.

At its core, Realm-X is built on a structured domain ontology and a set of shared business primitives
—such as transactions, actions, reports, metrics, and skills that enable AI systems to deeply understand and operate across the full context of property management workflows. This foundation allows us to build context-aware, action-oriented AI systems that go beyond simple assistance to power real automation and decision‑making.

We're seeking a Principal Machine Learning Engineer to help define and lead the next generation of AI systems within Realm-X, and to drive App Folio's long‑term autonomous Real Estate Performance Management (RPM) platform - autonomous AI agents that can deliver property management performance.

This is a company‑impact role
. You will own mission‑critical AI capabilities, shape long‑term technical strategy, and act as a technical visionary and advisor across teams and leadership.

You'll operate at the intersection of traditional machine learning, deep learning, and generative AI
, building systems that go beyond AI assistance into execution, automation, and optimization
.

This role is for someone who doesn't just build systems — but redefines how they should be built
.

• Architect & Lead: Help define the technical vision and architecture for AI systems across Realm-X in partnership with senior leadership.

• Scale Intelligent AI Agents: Design and deploy advanced AI Agentic systems that combine reasoning, planning, and execution, including multi‑agent orchestration across specialist agents (e.g., maintenance, leasing, accounting, collections).

• Improve the Foundation: Establish platform primitives and abstractions to enable context‑aware, action‑oriented AI that goes beyond simple assistance to true automation. Improve the standards for end‑to‑end ML systems: data collection, model training, evaluation, deployment, and inference infrastructure.

• Production Excellence: Architect and build scalable, multi‑modal, and real‑time AI applications, ensuring high‑quality deployment standards.

• ML for Autonomous Property Management: Drive App Folio's transition toward autonomous property management operations. Use existing LLMs today and instrument the proprietary data collection now that will let us selectively train, fine‑tune, and RL‑optimize open source LLM and SLM for the RPM domain — optimizing performance, latency, and cost.

• Reinforcement Learning for Agent Policies: Build the data and feedback loops needed to enable Reinforcement Learning over agent action policies in the partially observable, high‑stakes property management environment.

• Systems thinker: You think in terms of systems, platforms, and long‑term leverage, not just features.

• Production builder: You'…