Sierra hits $100M ARR in seven quarters and launches GhostWriter — an agent for building agents

Summary

Sierra reached $100M ARR in seven quarters, with Bret Taylor describing the company as currently in its ninth quarter. It works with 40% of the Fortune 50, including Singtel, Sky, Nordstrom, Prudential, and Cigna. Nordstrom went live with a voice agent in four weeks and ramped from 1% to 100% traffic in a single week. Next, the UK retailer, went live in six weeks; Cigna in eight.

GhostWriter

Sierra's headline launch is GhostWriter, an AI agent that builds customer experience agents through natural language. Rather than configuring agents through a web interface, users describe what they want — a warranty claims flow, a revised return window, a more empathetic tone — and GhostWriter performs the configuration on their behalf. Taylor says someone could upload an audio recording of a conversation and GhostWriter would produce the corresponding agent. The aspiration is to compress four-week implementations to four days.

The product reflects a broader bet that the web-app model — forms and fields in a browser as the interface to enterprise systems of record — is giving way to conversational AI. Sierra models agent behavior as goals and guardrails rather than scripted rules, which is what allows agents to handle free-form conversation while still staying on brand. The guardrail-width question is real: regulated industries narrow them, consumer brands may intentionally leave more room for the kind of human warmth that comes with some conversational range.

Japan expansion

Sierra acquired Opera, an 11-person Japanese AI company that had positioned itself as the Sierra of Japan. The acquisition is Taylor's vehicle for entering the Japanese enterprise market, pairing local market knowledge and existing client relationships with Sierra's full platform. Taylor describes it as an unusual model — a technical acquisition used specifically for geographic entry — and says he expects to report results in six months.

Go-to-market

Sierra targets mid-market and enterprise rather than self-serve, and Taylor is explicit that the business model is built around transformation, not just software deployment. A med-tech client with 40 call centers consolidating into one is the illustrative case: the technology is one-fifteenth of the problem. Change management, sequencing, and enablement are the rest, and Sierra positions itself as a partner rather than a vendor.

On enterprise GTM more broadly, Taylor argues that AI agents are the most promising tool for scaling sales consistency globally without fragmenting into regional variants of the same company. Sierra uses agents internally to equip sellers with product knowledge and RFP support, and Taylor frames the Japan acquisition partly through that same consistency lens.

Taylor's single sharpest indicator of whether a founder has enterprise GTM figured out: whether the CEO personally spends time with customers. Product and tech founders who delegate sales entirely, he argues, almost never crack it early.