This Startup Built the Infrastructure Powering Voice AI

In this episode of Founder Firesides, YC Managing Partner Jared Friedman talks to Dylan Fox, the Founder of Assembly AI (S17), which has raised $160M to date. AssemblyAI is the voice AI infrastructure platform powering 10,000 companies, including Granola, Zoom and Delta Airlines. https://www.assemblyai.com/ Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https://www.ycombinator.com/jobs Chapters: 02:08 - What AssemblyAI actually does 05:23 - Dylan learns to code and discovers ML 07:11 - The Amazon Echo moment 09:32 - Why Dylan built voice AI infrastructure 13:02 - Building AI before anyone cared 16:50 - The 2021 inflection point 24:13 - Real-time voice agents are here 28:26 - Inside AssemblyAI’s new voice models 45:33 - Lessons from hypergrowth 52:00 - The future of voice AI

Jared FriedmanhostDylan Foxguest

Mar 5, 202653mWatch on YouTube ↗

EPISODE INFO

Released: March 5, 2026
Duration: 53m
Channel: YC Root Access
Watch on YouTube: ▶ Open ↗

EPISODE DESCRIPTION

In this episode of Founder Firesides, YC Managing Partner Jared Friedman talks to Dylan Fox, the Founder of Assembly AI (S17), which has raised $160M to date. AssemblyAI is the voice AI infrastructure platform powering 10,000 companies, including Granola, Zoom and Delta Airlines. https://www.assemblyai.com/ Apply to Y Combinator: https://www.ycombinator.com/apply Work at a startup: https://www.ycombinator.com/jobs Chapters: 02:08 - What AssemblyAI actually does 05:23 - Dylan learns to code and discovers ML 07:11 - The Amazon Echo moment 09:32 - Why Dylan built voice AI infrastructure 13:02 - Building AI before anyone cared 16:50 - The 2021 inflection point 24:13 - Real-time voice agents are here 28:26 - Inside AssemblyAI’s new voice models 45:33 - Lessons from hypergrowth 52:00 - The future of voice AI

SPEAKERS

Jared Friedman
host
YC partner and host of YC Root Access who interviews founders about their startups and technology.
Dylan Fox
guest
Founder/CEO of AssemblyAI, building infrastructure and models for speech recognition and voice AI applications.

EPISODE SUMMARY

In this episode of YC Root Access, featuring Jared Friedman and Dylan Fox, This Startup Built the Infrastructure Powering Voice AI explores assemblyAI built voice infrastructure enabling real-time agents and audio understanding AssemblyAI provides voice AI infrastructure—APIs and models—used by products like note takers, contact centers, and emerging real-time voice agents at massive scale.

RELATED EPISODES