GoKawiilBret Taylor, co-founder and CEO of Sierra, speaking to CNBC at the World Economic Forum in Davos, Switzerland on Jan. 22nd, 2026.
Artificial intelligence startup Sierra is raising nearly a billion dollars in a new funding round, CNBC has learned, as venture capital investors search for winners in an ongoing deal spree.
The San Francisco-based company brought in $950 million in fresh capital at a $15.8 post-money valuation, led by Tiger and Google's GV. Benchmark, Sequoia, Greenoaks and other existing investors also participated.
The startup was founded three years ago by OpenAI chairman and former Salesforce co-CEO Bret Taylor, with former Google executive Clay Bavor. Taylor was also chief technology officer at Facebook , and chairman of Twitter when Elon Musk bought the social media network. The Sierra founders met at Google, where Taylor was largely credited with helping create Google Maps and Bavor led virtual reality efforts and Google Labs.
Sierra sells AI customer service agents and is positioning itself as a leader in a new class of software companies built on top of foundational models from OpenAI and Anthropic. According to Taylor, the company leverages a "constellation of models" alongside its own fine-tuned proprietary layers.
Sierra topped $150 million in annual recurring revenue, or ARR, in eight quarters, according to the company. That growth timeline is unprecedented in traditional software and highlights "intense demand in the market," Taylor said.
"There's a really big addressable market and immediate opportunity," Taylor said. "We've sort of digitized the last remaining analog channel, which is the telephone line — it's a better experience. You don't need to wait on hold. These agents are naturally multilingual."
Taylor estimated that $400 billion is spent annually on customer service. A bulk of that, he said, is moving to AI agents.