Bret Taylor’s AI Startup Sierra Raises $175M, Now Valued At $4.5 Billion

Sierra, the AI software startup co-founded by former Salesforce co-CEO Bret Taylor and longtime Google executive Clay Bavor, has reached a $4.5 billion valuation following its latest funding round. The company secured $175 million in new capital, led by Greenoaks Capital, with participation from Thrive Capital, Iconiq, Sequoia Capital, and Benchmark. This latest funding round underscores the confidence investors have in Sierra’s growth potential and the expertise of its founding team.

Founded just over a year ago, Sierra focuses on AI-powered customer service solutions, providing chatbots to major clients including WeightWatchers and Sirius XM. Sierra’s platform also integrates with other enterprise systems, enabling AI agents to handle tasks autonomously on behalf of customers. The startup aims to differentiate itself from competitors by minimizing “hallucinations” — instances where AI models generate inaccurate information — making it a reliable option in the crowded chatbot market.

Sierra’s AI offers further customization, allowing companies to adapt the chatbot’s personality to align with their brand. Leveraging a “constellation” of generative AI models from OpenAI, Anthropic, and Meta, Sierra’s platform works to enhance accuracy and consistency in customer service interactions.

Taylor and Bavor both have a deep history in customer service technology. Before co-founding Sierra, Taylor spent nearly a decade at Salesforce, where he also founded Quip, a productivity tool Salesforce acquired for $750 million in 2016. Bavor, a former Google executive, oversaw Gmail and Google Drive, among other products.

Sierra’s rapid growth reflects a broader shift in AI investment. Following the popularity of OpenAI’s ChatGPT, funding has moved toward applications that directly serve business needs and generate stable revenue, as opposed to more costly foundational models.