Principal ML Engineer

Salary: $264,000 - 330,000 per year Requirements:

• We require a masters or Ph.D. in Computer Science, Machine Learning, or a closely related discipline.
• We expect 10+ years of experience building software systems, with substantial emphasis on ML and AI, or equivalent impact.
• We look for a track record that spans both academic research and production delivery.
• We need deep expertise in traditional machine learning, deep learning, and generative AI/LLMs, including prompting, fine-tuning, RAG, agents, and tool use.
• We require hands-on experience with LLM post-training at meaningful scale, such as SFT, RLHF, DPO, and/or RL.
• We expect strong command of the full ML lifecycle, from data extraction and training through evaluation, deployment, and production integration.
• We need advanced proficiency in Python, PyTorch, NumPy, AWS, Docker, SQL, embeddings, and RAG.
• We look for experience with agent tooling such as LangChain, LangGraph, and observability platforms like LangSmith.
• We require experience designing and operating production-grade ML systems at scale.
• We value applied experience with ontology-driven systems, knowledge graphs, or semantic layers for modeling business domains in AI systems.
• We expect familiarity with AI-native engineering workflows and coding tools such as Copilot, ChatGPT, and code generation tools.
• We value a systems-thinking mindset, strong ambiguity tolerance, cross-team influence, originality, ownership, speed, collaboration, and a genuine interest in the real estate industry.

• We will rely on you to help define the technical vision and architecture for AI systems across Realm-X in partnership with senior leadership.
• You will design and deploy advanced agentic AI systems that combine reasoning, planning, execution, and multi-agent orchestration across specialist domains such as maintenance, leasing, accounting, and collections.
• You will establish platform primitives and abstractions that enable context-aware, action-oriented AI and strengthen end-to-end ML standards across data collection, training, evaluation, deployment, and inference infrastructure.
• You will architect and build scalable, multimodal, real-time AI applications with a high bar for production quality.
• You will help drive our move toward autonomous property management operations by leveraging current LLMs and instrumenting proprietary data collection for future selective training, fine-tuning, and RL optimization of open-source LLMs and SLMs.
• You will build the data and feedback loops needed to support reinforcement learning over agent action policies in a partially observable, high-stakes property management environment.

• Agentic AI
• AI
• AWS
• Architect
• ChatGPT
• Copilot
• Docker
• Fine-tuning
• Support
• LLM
• Machine Learning
• PyTorch
• Python
• RAG
• SQL
• numpy
• Cloud
• AI Agents
• Excel
• Model Training

More:

We are AppFolio, a technology leader building the AI-native platform that is transforming the real estate industry. Our Realm-X platform powers intelligent products such as an assistant, AI-driven workflows, and autonomous agents, creating context-aware automation for property management. This is a high-impact principal-level role with ownership of mission-critical AI capabilities and long-term technical strategy. We offer a comprehensive total rewards package, including a competitive base salary range of $264,000 to $330,000, along with additional benefits and potential discretionary bonuses for eligible full-time employees. We support growth through coaching, mentorship, and meaningful work, and we foster a flexible, connected hybrid culture built around impact, learning, and collaboration. Our hiring process includes an in-person meeting for late-stage candidates, and we are committed to equal opportunity and an inclusive workplace.

last updated 33 week of 2026