Sierra raises $950 million as competition to own enterprise AI intensifies.

Bret Taylor’s AI startup Sierra announced Monday that it has closed a $950 million funding round led by Tiger Global and GV, pushing its post-money valuation to more than $15 billion. The raise gives Sierra more than $1 billion in capital that it will use to become the “global standard” for AI-powered customer experiences.

Like many AI companies, Sierra has been very active in promoting its own growth in a crowded market. The company says it started a few years ago with just four design partners. The company now counts more than 40% of Fortune 50 companies as customers and claims that agents operating on its platform handle billions of interactions, from mortgage refinancing to processing insurance claims, managing returns and supporting nonprofit fundraising campaigns.

In fact, the funding news follows tremendous sales growth shared by Sierra. Sierra first announced it had hit $100 million in annual recurring revenue in late November, then posted in early February that it had hit $150 million in ARR.

This pace reflects both the urgency companies feel to deploy AI and the costs associated with it. Taylor, chairman of OpenAI and former co-CEO of Salesforce, said the best outcome of agent AI is reduced costs and increased revenue for customers, but the ramp-up phase before those returns are realized can be expensive.

That very scenario came up in a conversation at one of TechCrunch’s StrictlyVC events last week. Uber CTO Praveen Neppalli Naga said in a conversation with this editor that Uber “exceeded our (AI) budget” shortly after opening the door to its agent AI tools late last year. He also said the company is starting to see meaningful results.

He added that across a staff of about 8,000 engineers and technical staff, about 10% of all code produced by the company is now generated autonomously. “Ten percent of our size is huge.” As a proof of concept, Uber tasked one team with building a new hotel booking integration using only agent workflows. “Work that would normally take a year was completed in six months,” he said.

Sierra is also moving to expand what its platform can do beyond customer-facing agents. Last April, the company launched Ghostwriter, an “agent-as-a-service” tool designed to build other agents. Users describe in natural language what they need, and Ghostwriter automatically creates and deploys expert agents to handle it.

For Taylor, the tool highlights a broader paper he presented at last month’s HumanX conference in San Francisco. He argued that many enterprise software tools are rarely used. Employees log in to Workday when they join and again during open enrollment, and that’s it. The future Sierra and its investors envision is one in which people will never have to navigate complex systems at all.