Sierra, an enterprise software company specializing in AI agents, has raised $350 million in fresh funding at a $10 billion valuation, with Greenoaks leading the round. Founded just 18 months ago, the company has quickly gained traction across major industries, including financial services, healthcare, retail, telecommunications, and consumer services. More than 20% of its customers generate revenues above $10 billion, and over half exceed $1 billion.
Today, Sierra serves hundreds of clients, among them some of the most highly regulated and recognizable brands worldwide. The company’s AI agents handle a wide range of daily interactions, from financial transactions and healthcare support to retail orders and technical troubleshooting. In retail alone, they reach over 90% of Americans, while in healthcare, they assist more than half of U.S. families.
Sierra plans to use the new capital, combined with strong revenue growth, to strengthen its platform, expand in the United States, and build a broader international presence in Europe and Asia. Its focus remains on improving agent development, driving customer satisfaction, and supporting businesses in creating more effective and personalized customer experiences at scale.