Infra for Building Conversational Voice AI Retell AI is a powerful platform for building production ready voice AI. We recently closed a $4.5M seed round and achieved remarkable growth, reaching $3M in revenue within six months. Retell AI is proudly backed by Alt Capital, Y Combinator, and other leading investors. Our team is composed of experts from Meta, Google, and TikTok, and we operate out of our in-person office in Redwood City.