Sierra, an AI-focused software startup co-founded by former Salesforce co-CEO Bret Taylor, announced on Monday that it raised $175 million in a new funding round led by Greenoaks Capital, boosting its valuation to $4.5 billion. This financing comes within a year of Sierra’s public launch, marking Taylor as one of Silicon Valley’s most closely watched entrepreneurs. Sierra specializes in enhancing AI-driven customer service for clients like WeightWatchers and Sirius XM. Sources familiar with the company’s performance reported to Reuters earlier