AI voice startup Vapi has reached a $500 million valuation following a successful $50 million Series B funding round. The financing was led by Peak XV Partners and included participation from Microsoft M12, Kleiner Perkins, and Bessemer Venture Partners, bringing Vapi's total funding to $72 million. The round coincides with a major deployment where Amazon Ring selected Vapi to handle all of its inbound customer calls, securing the company's position as a key player in the rapidly evolving AI voice infrastructure market. The partnership originated in mid-Q4 of the previous year when Ring faced a surge in customer support inquiries. The company evaluated more than 40 AI voice vendors before choosing Vapi. This decision was driven by Vapi's ability to offer Ring engineers granular control over AI agent behavior during live interactions. Jason Mitura, vice president of software development at Amazon Ring, confirmed that the deployment has improved customer satisfaction scores. He noted that Ring's teams can now tune the AI agent experience without requiring constant engineering support, a significant advantage over other tools that promise outcomes but fail to deliver. As a result, Ring now routes 100% of its inbound traffic through Vapi. Founded by Jordan Dearsley and Nikhil Gupta, Vapi evolved from an AI therapy app created in 2023. The founders realized that while the consumer product had limited demand, the underlying low-latency voice infrastructure was highly valuable for businesses. They pivoted to build a platform for companies to deploy and manage voice agents across various use cases, including customer support, lead qualification, and appointment scheduling. Since launching the platform publicly in 2024, Vapi has processed over one billion calls. Currently, the system handles between one million and five million calls daily, with enterprise clients comprising the majority of this volume. Beyond Amazon Ring, Vapi's client list includes Kavak, Instawork, New York Life, UnityAI, Cherry, and Intuit. The company also maintains a self-serve developer platform used by over one million developers. This large developer footprint allowed Vapi to test its infrastructure at scale before securing major enterprise contracts. According to investor sources, the startup is operating at an annual recurring revenue run rate in the eight figures. Vapi operates within a competitive landscape that includes companies like Sierra, Decagon, Bland, and ElevenLabs. However, Dearsley emphasizes that Vapi differentiates itself by focusing on the infrastructure and orchestration layer rather than pre-packaged applications. This approach targets enterprises seeking greater control over reliability, compliance, and model behavior. With approximately 100 employees, the company plans to utilize the new funding to expand its engineering, infrastructure, and go-to-market teams. Dearsley described the core challenge of the industry as taming the unpredictable nature of AI models to provide reliable value to the world.