Every minute a customer sits on hold, a business loses money—and patience. The average American spends 13 hours a year on hold. This week's startup, Retell AI, is replacing hold music with AI agents that actually pick up the phone. And they just blew past $40M in annual revenue. Let's check them out!

⚾️ The Elevator Pitch

Call centers are expensive, slow, and soul-crushing—for both sides of the phone. Companies spend billions on conversational AI trying to fix it, yet most \"press 1 for sales\" phone trees still feel like they were built in 2005. The conversational AI market is projected to hit $82 billion by 2034, and the race is on to build voice agents that don't sound like robots reading a script.

Enter Retell AI. Founded in 2023 by five ex-big-tech engineers—Bing Wu (CEO, ex-ByteDance PM), Zexia Zhang (CTO, ex-Google speech/NLP), Weijia Yu (ex-Meta), Evie Wang (ex-ByteDance), and Todd Li (ex-Google)—the company built a platform that lets businesses deploy AI voice agents in weeks, not months. Their secret sauce? ~600ms response latency and proprietary turn-taking models that know when to talk and when to listen. They went through Y Combinator's W24 batch, raised a $4.6M seed round led by Alt Capital, and now power 40 million+ AI phone calls every month for clients like DoorDash, Lenovo, and the San Antonio Spurs.

👇 The Drop Down

🌐 Website: retellai.com
📅 Founded: 2023
👥 Founders: Bing Wu (CEO), Zexia Zhang (CTO), Weijia Yu (co-founder), Evie Wang (CMO), Todd Li (President)
💰 Stage: Seed - $5.1M raised from Alt Capital, Y Combinator, Carya Venture, plus angels like Aaron Levie (Box) and Michael Seibel (Twitch/YC)
📈 Traction: $40M+ ARR, 40M+ calls/month, 1,000+ business customers, already profitable
🔮 Tech Trend: Voice AI / Conversational AI Agents
🎯 Target Market: Enterprise call centers, healthcare, insurance, financial services, home services
🏢 Location: San Carlos, CA (~20-person team, all on-site)

🔎 Why We Like It

📈 Growth That Defies Gravity: From $3M ARR at their seed round to $40M+ ARR in roughly 16 months—with just 20 employees. That's $1.7M revenue per employee. Brex ranked them #4 on their list of the 50 fastest-growing software vendors and the #1 voice AI platform. They're already profitable.
👫 Big-Tech DNA, Startup Speed: Five founders who collectively logged decades at Google, ByteDance/TikTok, and Meta aren't just building another wrapper. Zexia led speech translation at Google; Bing ran B2B products for billions of users at TikTok. Their proprietary turn-taking technology is what makes their agents sound genuinely human—not just fast, but conversationally intelligent.
🏎️ Enterprise Clients, Real Results: Retell AI isn't just demo-ware. Sunshine Loans handles 700K+ monthly applications with 75-80% of calls fully resolved by AI. Everise contained 65% of calls and eliminated wait times entirely. With HIPAA, SOC2, and GDPR compliance baked in, they're winning the trust of industries that don't take chances.

🤝 Get Involved with Retell AI

📱 Try Retell AI - $10 free credits to start, no platform fees
💼 Join the team - hiring 16+ roles across engineering, product, and more!
📰 Read about their $40M ARR milestone
🐦 Follow Retell AI on Twitter
📧 Check out the developer docs

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🚀 Retell AI: Your Call Center, But It Never…