AssemblyAI CEO Dylan Fox on 120 Million Voice Conversations a Week
AssemblyAI CEO Dylan Fox on 120 Million Voice Conversations a Week  
Podcast: Sourcery
Published On: Fri Jul 31 2026
Description: Dylan Fox is the founder and CEO of AssemblyAI, the voice AI infrastructure platform behind AI notetakers, medical scribes, drive through ordering, contact centers and humanoid robots. AssemblyAI went through Y Combinator's first AI batch in 2017 and now serves over 1 million developers with roughly 100 million API calls a day.We get into the volume numbers, why weekly conversations are up over 800% in three years, the three macro trends pulling voice into everything, why coding agents turned small businesses into API customers, how data mixture drives 75% of model quality, the humanoid robot speaker problem, on device models, and the disclosure question the entire voice agent industry is avoiding."It's very easy to optimize for a public open source benchmark. It's very hard to optimize across all these real world applications."We cover › 120 million weekly conversations and 4x YouTube's daily voice volume › Coding agents expanding the TAM by 100x › Context aware voice models and the McDonald's ordering problem › Why humanoid robots can't disambiguate speakers › Whether voice agents should disclose they are AIDylan Fox: https://x.com/YouveGotFoxMolly O’Shea: https://x.com/MollySOShea Sourcery: ⁠https://x.com/sourceryy 𝐄𝐏𝐈𝐒𝐎𝐃𝐄 𝐋𝐈𝐍𝐊YouTube: https://youtu.be/xAF7HkX2DXI𝐒𝐏𝐎𝐍𝐒𝐎𝐑𝐒• Brex—The modern finance platform, combining the world’s smartest corporate card with integrated expense management, banking, bill pay, & travel. https://brex.com/sourcery • MongoDB–Millions of developers and more than 65,200+ customers across industries, including ~75% of the Fortune 100, rely on MongoDB for their most important applications. With integrated capabilities for operational data, search, real-time analytics, & AI-powered data retrieval, MongoDB helps organizations everywhere move faster, innovate more efficiently, & simplify complex architectures. https://mongodb.com/ai• AssemblyAI–Millions of developers use AssemblyAI to power their voice ai applications and features. One API gives you access to best-in-class speech-to-text, voice agent, and speech understanding models for both pre-recorded and real-time audio.  Granola, ClickUp & HeyGen are scaling with AssemblyAI - get $50 of free credits today at http://AssemblyAI.com/sourcery𝐓𝐈𝐌𝐄𝐒𝐓𝐀𝐌𝐏𝐒(00:00) Dylan Fox, Founder & CEO at Assembly AI(01:06) AssemblyAI's voice traffic just beat YouTube by 4x(03:33) $100K in GPU credits that started it all(06:39) Why Voice AI is inflecting right now(10:11) AssemblyAI's infrastructure-first strategy(12:41) Handling 120 million weekly calls(14:49) How AI agents are rewriting Internal Ops at AssemblyAI(17:05) The Sovereign AI problem nobody's solved for voice(18:26) Is the Keyboard and Mouse finally dying?(22:33) The problem Humanoid Robotics hasn't solved yet(25:14) The real problem behind translating languages(29:27) Can AI actually talk to animals?(31:24) The real reason Open-Source benchmarks lie to you(34:20) Building websites in chat rooms as a kid(36:48) On-Device AI models are about to change everything(43:03) The people who shaped Dylan's career