Senior ML Engineer - Voice & AI Agent Platforms

Appfolio; Santa Barbara (CA); On-site; USD 167,000 - 230,000; Full time

Job summary

AppFolio is seeking a Senior Machine Learning Engineer to design the next generation of voice and conversational AI agents in Realm-X. You will shape production voice pipelines and multi-channel experiences across our AI-native platform, collaborating with Product, Voice, and ML Platform teams to deliver scalable solutions.

You will lead a small pod of ML engineers, optimize latency, and refine agent quality with well-defined KPIs, while leveraging LangChain tools, Twilio-based telephony, and

Qualifications

• Agent frameworks: Deep, shipped experience with LangChain, LangGraph, LangSmith, and LangChain Deep Agents (or equivalent).
• Voice stack: Experience with voice-to-voice models and STT/TTS pipelines; understands trade-offs in end-to-end vs modular architectures.
• LLM fluency: Strong grasp of LLM reasoning, tool use, structured output, and latency trade-offs.
• Telephony & cloud: Production experience with Twilio and AWS.
• Engineering: Expert Python, async programming, and WebSockets for real-time, bidirectional streaming.
• ML fundamentals: Deep learning, model evaluation, inference optimization; deploy with Docker on AWS.
• Leadership: Ability to lead a small team and mentor engineers.

Responsibilities

• Architect and ship voice and text agent pipelines for real-time customer interactions.
• Balance reasoning depth and latency across frontier LLMs and routing strategies.
• Lead a pod of ML and platform engineers and improve agent evaluation and incident response.
• Define KPIs, eval harnesses, and acceptance criteria for agent quality.
• Drive fine-tuning and inference optimization for voice latency and cost.

Skills

Agent frameworks

Voice tech

LLM fluency

Telephony & cloud

Python

Async programming

WebSockets

Deep learning

Docker on AWS

Leadership

Education

Bachelor’s, Master’s, or Ph.D. in CS or related field

Tools

Twilio

AWS

LangChain

Docker

Job description

AppFolio is seeking a Senior Machine Learning Engineer to design the next generation of voice and conversational AI agents in Realm-X. You will shape production voice pipelines and multi-channel experiences across our AI-native platform, collaborating with Product, Voice, and ML Platform teams to deliver scalable solutions.

You will lead a small pod of ML engineers, optimize latency, and refine agent quality with well-defined KPIs, while leveraging LangChain tools, Twilio-based telephony, and