SIERRA

Bret Taylor had already done the impossible twice. He co-created Google Maps.

He later became co-CEO of Salesforce and chaired Twitter's board during the messy Elon Musk takeover. Clay Bavor spent 18 years at Google, most recently running its Labs group.

The two friends left their big jobs in 2023 to build something together. They picked customer service on purpose.

It is the least glamorous corner of software. Their logic was simple.

Companies hate their support costs. Customers hate waiting on hold.

AI that actually resolves problems could fix both sides at once. They launched Sierra in February 2024 with $110 million from Sequoia and Benchmark.

Companies pay Sierra to run their customer service with AI agents instead of hiring rooms full of humans. The agent talks to your customers over chat.

It answers questions. It processes returns.

It updates subscriptions. Here is the clever part.

Sierra charges based on outcomes, not seats. Brands pay when the AI actually resolves a problem, not just for having the software installed.

That pricing is unusual. Most software charges a flat monthly fee no matter what.

Sierra only gets paid when the bot does the job.

The core product is the Sierra AI agent. It is a branded customer service bot that companies deploy on their website, app, and phone lines.

It handles the boring stuff. Order tracking.

Refunds. Password resets.

Account changes. Sierra also built its own tools to test and monitor these agents so they do not make things up.

In 2024 the company added a voice version that talks to customers on the phone. The whole pitch is one AI agent that carries your brand's name and never sleeps.

Sierra went straight for big brands, not tiny startups. SoFi, Ramp, ADT, Sonos, and Brex all signed up early.

The trick was trust. Enterprises are terrified of an AI bot going rogue and insulting a customer.

So Sierra built guardrails and let each company control exactly how the agent behaves. Bret Taylor's contacts did the rest.

When the former Salesforce boss calls a Fortune 500 CEO, they pick up. Sierra hit $100 million in yearly revenue seven quarters after launch.

That makes it one of the fastest-growing software companies ever.

Everyone is building AI customer service agents right now. Decagon raised money at a $4.5 billion valuation.

Salesforce, ServiceNow, and Intercom all shipped their own agents. Sierra is not the cheap option.

It sells premium AI to giant companies that move slowly. The bigger risk sits underneath the product.

Sierra does not make its own AI models. It rents them from providers like OpenAI and Anthropic.

If those model makers decide to compete directly, Sierra's edge gets thin fast. A $10 billion valuation on roughly $100 million in revenue leaves zero room for a stumble.

Greenoaks Capital is the big believer here. It led both the $175 million round in 2024 and the $350 million round in 2025.

Sequoia Capital and Benchmark wrote the first checks at launch in February 2024. In other words, the most respected names in venture capital all wanted in.

That is partly the product and partly Bret Taylor. Investors bet on founders who have already built billion-dollar things.