Sierra Raises $350 Million in Additional Capital at a Valuation of $10 Billion

Sierra, an AI-powered customer experience platform, led by Bret Taylor and Clay Bavor, has raised $350 million in additional capital led by Greenoaks.

In just 18 months, Sierra has partnered with hundreds of major brands across the Financial Services, Healthcare, Telecommunications, Retail, and Consumer Services. Its agents now reach 90% of Americans in retail and over half of US families in healthcare, while also powering leading banks and fintechs. From refinancing homes to fixing internet connections, Sierra agents help hundreds of millions of people with faster, more human AI-driven experiences.

New funding and strong growth will accelerate Sierra’s investments in its platform, U.S. expansion, and international reach. Agent OS enables teams and developers to build powerful AI agents, with upcoming advancements focused on easier onboarding, AI-driven improvements, and broader use cases beyond customer service. Sierra is also expanding its presence in Europe and Asia to bring its technology to more companies worldwide.