What is Sierra?

What is Sierra?

Sierra is an enterprise conversational AI platform that enables companies to deploy branded AI agents for customer experience — handling support, sales, and account management across chat, voice, email, SMS, and WhatsApp. Founded in 2023 by former Salesforce co-CEO Bret Taylor and ex-Google VP Clay Bavor, Sierra reached $200M ARR by May 2026 and now counts more than 40% of the Fortune 50 among its 100+ enterprise customers.

Sierra's Agent Operating System (Agent OS) gives enterprise brands a way to build AI agents that go beyond scripted FAQ answering — agents that can update subscriptions, process returns, reschedule deliveries, and complete multi-step workflows by connecting to CRM systems, order management platforms, and other systems of record. The platform supports 34+ languages and is available 24/7/365, with a voice pipeline that surpassed chat as Sierra's primary channel by September 2025 — less than a year after voice launched.

Sierra was built around four core products: Agent Studio (a no-code builder for CX teams), Agent SDK (a developer-facing programmatic layer), Ghostwriter (a natural language agent builder launched March 2026 that produces production-ready agents from SOPs, transcripts, and audio recordings), and the Agent Data Platform (persistent cross-session memory launched November 2025). Sierra deploys agents in weeks rather than months and publishes containment rates above 70% and CSAT scores above 4.5/5 across its customer base.

Named customers include Rocket Mortgage, SiriusXM, Nordstrom, Cigna, Nubank, Wayfair, Chime, Rivian, Ramp, ADT, Singtel, Sutter Health, and Minted. Sierra differentiates through a fully managed deployment model, outcome-based pricing, and a concentrated focus on Fortune 500 consumer brands — competing at the top of the enterprise AI agent market against Salesforce Agentforce, Decagon, and Intercom Fin.

Sources:Sierra Product OverviewTechCrunch: Sierra raises $950MSierra Voice Turns One Blog

What does Sierra offer?

Sierra's platform spans AI agent development, omnichannel deployment, analytics, and enterprise integrations — all governed by an outcome-based pricing model with no self-serve tier.

Sources:Sierra Product PageSierra Agent OS 2.0 BlogSierra Ghostwriter Launch

How does Sierra make money?

Sierra charges enterprises on an outcome-based model — customers pay per successful AI-resolved conversation or interaction, bundled into multi-year enterprise agreements with high-touch implementation services. There are no self-serve tiers or published per-seat rates.

All engagements go through a direct enterprise sales process. Sierra does not publish list pricing, but third-party estimates consistently place baseline annual contracts at approximately $150,000 per year, with first-year total costs of $200,000–$350,000 or more when implementation and professional services are factored in. Larger multi-channel deployments with high conversation volumes can reach $350,000–$750,000+ annually. Setup fees alone are estimated at $50,000–$200,000 depending on complexity. The outcome-based model means Sierra earns more as the agent handles more volume, directly aligning Sierra's revenue with the customer's AI containment rate and deployment scale.

Growth is driven by expansion within existing enterprise logos as customers add channels, languages, and use cases beyond the initial deployment. Sierra's $200M ARR as of May 2026 — up from roughly $26M at end-of-2024 and $150M by February 2026 — reflects both rapid new logo acquisition and a strong land-and-expand motion within Fortune 50 accounts. The company also offers Sierra University, a training program where enterprise teams learn to design and deploy production-ready agents, deepening platform stickiness.

Sierra's go-to-market is anchored by a direct enterprise field sales team led by Eric Eyken-Sluyters (President of Field Operations, formerly 23 years at Salesforce running Agentforce). Partnerships with BPO firms like ibex extend reach into CX outsourcing channels. Ghostwriter (launched March 2026) is also reducing implementation friction at scale by enabling customers to self-serve new agent workflows without relying on professional services for every iteration.

Sources:Sierra AI Pricing Analysis — Fin AISacra: Sierra Revenue & Business ModelSierra AI Pricing — eesel AI

Who leads Sierra?

Sierra was co-founded by two marquee operators — Bret Taylor (CEO) and Clay Bavor (Co-Founder) — and has added key enterprise go-to-market leadership as it scales past $200M ARR.

Sources:Sierra About PageEric Eyken-Sluyters Joins SierraShopifreaks: Eyken-Sluyters Departs Salesforce for Sierra

How do you contact Sierra's leadership?

Sierra's verified email format is {first}@sierra.ai (used by 81.4% of Sierra employees per RocketReach), with {first}.{last}@sierra.ai as the second-most common pattern. No official press or sales contact email is publicly listed on sierra.ai; the addresses below follow the company's verified first-name format and should be treated as inferred unless confirmed through a direct channel.

• Bret TaylorCo-Founder & CEObret@sierra.ai
• Clay BavorCo-Founderclay@sierra.ai
• Eric Eyken-SluytersPresident, Field Operationseric@sierra.ai

Sources:Sierra About PageRocketReach Sierra Email Format

How much funding has Sierra raised?

Sierra has raised $1.585 billion in total equity funding across four disclosed rounds since its 2023 founding, most recently a $950M Series E in May 2026 at a $15.8 billion post-money valuation co-led by Tiger Global and GV (Google Ventures).

Seed Round (February 2024): $110M at a ~$1B valuation, led by Sequoia Capital and Benchmark, with participation from Next Play Ventures and First Round Capital. This round coincided with Sierra's public launch and first four named enterprise customers: WeightWatchers, SiriusXM, Sonos, and OluKai. Board seats went to Ravi Gupta (Sequoia) and Peter Fenton (Benchmark).

Series A (October 2024): $175M led by Greenoaks Capital at a $4.5B valuation — a 4.5× valuation step-up in under eight months. ARR was approximately $20M at announcement, making this one of the richest early-stage multiples in enterprise SaaS history. Series B (September 2025): $350M led by Greenoaks Capital at a $10B valuation — doubling the Series A valuation in roughly 11 months. Sierra was approaching $100M ARR at the time and had just signed San Francisco's largest new tech office lease of 2025 (300,000 sq ft at 185 Berry Street, China Basin).

Series E (May 2026): $950M co-led by Tiger Global and GV (Google Ventures), with Benchmark, Sequoia, and Greenoaks all re-upping. Post-money valuation: $15.8B. Sierra had reached $200M ARR at the time of the round — representing nearly 8× growth in 17 months from end-of-2024's ~$26M ARR. The round is one of the largest single private AI fundraises of 2026. Prior to the Series E, Sierra also completed three acquisitions in early 2026: Receptive AI (voice agents, March 2026), Opera Tech (Japan enterprise AI, March 2026), and Fragment (Paris-based AI operations startup and YC alum, April 2026).

Sources:TechCrunch: Sierra raises $950MFortune: Sierra $110M Seed RoundYahoo Finance: Sierra Series ESacra: Sierra Funding & Valuation

How did Sierra get here?

Sierra went from stealth to $200M ARR and a $15.8B valuation in under three years, driven by a marquee founding team, rapid enterprise adoption, three acquisitions, and four funding rounds totaling $1.585B.

Sources:TechCrunch: Sierra $100M ARRYahoo Finance: Sierra Series ESierra acquires Fragment in FranceSierra acquires Receptive AISierra acquires Opera Tech in Japan

Who are Sierra's competitors?

Sierra competes in the enterprise AI agent and conversational AI space against incumbent helpdesk vendors adding AI, pure-play AI agent startups, and CRM platforms extending into CX automation.

Sources:Top Sierra Alternatives 2026 — Fin AIDecagon vs Sierra 2026 — eesel AISierra AI Competitors — Cresta