Lead ML Engineer - Real-Time Voice & Text AI Agents

AppFolio; Atlanta (GA); On-site; USD 167,000 - 209,000; Full time

Job summary

AppFolio is hiring a Senior Machine Learning Engineer to design and ship the next generation of voice and conversational AI agents within Realm-X. You’ll work at the intersection of LLM agent frameworks, real-time voice tech, and streaming infrastructure to deliver low-latency experiences for our real estate customers.

You will collaborate with Product, Voice, and ML Platform teams to translate cutting-edge research into reliable, scalable solutions that power multi-channel interactions across

Qualifications

• Agent frameworks: Deep, shipped experience with LangChain, LangGraph, LangSmith, and LangChain Deep Agents (or equivalent agent frameworks).
• Voice stack: Hands-on with Voice-to-Voice models and traditional TTS / STT pipelines; understands the trade-offs between end-to-end voice models and modular STT → LLM → TTS architectures.
• LLM fluency: Strong grasp of LLM reasoning behavior, tool use, structured output, and reasoning-vs-latency trade-offs across providers.
• Telephony & cloud: Production experience with Twilio (or comparable telephony) and AWS.
• Engineering: Expert Python, async programming, and WebSockets for real-time, bidirectional streaming.
• ML fundamentals: Solid foundation in deep learning, model evaluation, and inference optimization; able to deploy with Docker on AWS.
• Leadership: Demonstrated ability to lead a small team, mentor engineers, and partner credibly with Product and Design.

Responsibilities

• Ship Voice & Text Agents: Architect and ship voice and text agent pipelines that handle real-time, multi-turn customer interactions.
• Reasoning vs. Latency: Make principled trade-offs between reasoning depth and latency across frontier LLMs, smaller models, and routing strategies.
• Lead a Pod: Lead a small pod of ML and platform engineers; raise the bar on agent evaluation, observability, and incident response.
• Define Quality: Partner with Product and Voice channel teams to define KPIs, eval harnesses, and acceptance criteria for agent quality.
• Optimize for Voice: Drive selective Small Language Model (SLM) fine-tuning and inference optimization for voice latency and cost.

Skills

LangChain

LangGraph

LangSmith

LangChain Deep Agents

Python

Async programming

WebSockets

LLM reasoning

Leadership

Tools

Twilio

AWS

Docker

Job description

AppFolio is hiring a Senior Machine Learning Engineer to design and ship the next generation of voice and conversational AI agents within Realm-X. You’ll work at the intersection of LLM agent frameworks, real-time voice tech, and streaming infrastructure to deliver low-latency experiences for our real estate customers.

You will collaborate with Product, Voice, and ML Platform teams to translate cutting-edge research into reliable, scalable solutions that power multi-channel interactions across