Sierra, the enterprise AI agent platform founded by Bret Taylor, is raising $950 million led by Tiger Global and GV, pushing its post-money valuation above $15 billion. Taylor, who also chairs OpenAI and previously co-led Salesforce, founded Sierra to replace traditional enterprise software interfaces with autonomous AI agents.
The company claims over 40% of the Fortune 50 as customers, with agents handling billions of interactions across mortgage refinancing, insurance claims, and customer service. Revenue has grown rapidly, reaching $150 million in annual recurring revenue by early February, up from $100 million in late November.
Sierra recently launched Ghostwriter, a tool that autonomously builds and deploys specialized AI agents from natural language descriptions. Taylor’s broader thesis holds that most enterprise software goes largely unused, and that agentic AI will eliminate the need to navigate complex systems entirely. The raise gives Sierra over $1 billion in total capital to pursue that vision.