About the job
ABOUT RETELL AI
At Retell AI, we're redefining the call center landscape through innovative voice AI technology. In just 18 months since our inception, our AI voice agents have been adopted by thousands of businesses, streamlining their sales, support, and logistics operations that previously relied on large teams of human agents. Supported by prominent investors such as Y Combinator and Alt Capital, we’ve experienced remarkable growth, scaling from $5M to $36M ARR with a dedicated team of 20.
Our ambitious vision for 2026 is to create a modern customer experience platform where entire contact centers are powered by AI. We aim to go beyond basic automation, developing intelligent AI “workers” capable of functioning as frontline agents, quality assurance analysts, and managers — continuously executing, assessing, and enhancing customer interactions.
As we continue to expand rapidly, we're on the lookout for passionate innovators eager to tackle challenging technical problems, accelerate progress, and make a significant impact in one of the fastest-growing voice AI startups. Join us in shaping the future!
Recognized as a top 50 AI app in the a16z list: https://tinyurl.com/5853dt2x
Ranked #4 on Brex's Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025
One of the top-ranking startups on: https://leanaileaderboard.com/
ABOUT THE ROLE
This role is perfect for machine learning researchers who are passionate about pushing the boundaries of real-time AI. As a Founding Machine Learning Research Engineer at Retell, you'll focus on enhancing the capabilities of our human-like voice agents in complex, real-world settings.
Your responsibilities will include exploring novel approaches within large language models and audio processing, designing innovative evaluation methodologies, and prototyping systems that enhance reasoning, reduce latency, and improve conversational quality. Your research will directly impact production systems, merging cutting-edge research with practical deployment.
If you're thrilled by the prospect of solving complex ML challenges, rapidly experimenting, and influencing the performance of voice AI systems, this is a unique opportunity to make a difference at scale.

