# Sierra Conversational AI · London · Series B Sierra builds an enterprise platform for conversational AI agents that handle customer service across chat, voice, email, SMS and other channels, branded and tuned for each company's needs. Founded in 2024 by former Salesforce co-CEO Bret Taylor and Clay Bavor, it targets large enterprises and counts a substantial share of the Fortune 50 among its customers, with reported ARR above $150M. The company is headquartered in San Francisco and operates a London office serving the UK and Europe. It raised a $950M Series E in May 2026 at a $15.8B valuation, with total funding exceeding $1.5B from investors including Benchmark, Sequoia, Greenoaks, Tiger Global and GV. - Website: https://sierra.ai - Careers: https://sierra.ai/careers - Sector: [Voice & Conversational AI](https://aistartupslist.co.uk/sector/voice-ai.md) ## Facts - Funding stage: Series B - Total raised: $1.5B+ - Founded: 2024 - Headquarters: San Francisco, USA - Team size: 201-500 ## Notable investors Benchmark, Sequoia Capital, Greenoaks, Tiger Global, GV, ICONIQ ## Open UK & remote roles - [Enterprise Account Executive, Europe](https://aistartupslist.co.uk/company/sierra/enterprise-account-executive-europe-18a6ac.md) · London (posted 2025-04-11) - [Software Engineer, Agent](https://aistartupslist.co.uk/company/sierra/software-engineer-agent-mymmkj.md) · London (posted 2025-02-13) - [Product Manager, Agent Development (German speaking)](https://aistartupslist.co.uk/company/sierra/product-manager-agent-development-german-speaking-475f4t.md) · London (posted 2025-08-21) - [Product Manager, Agent Development](https://aistartupslist.co.uk/company/sierra/product-manager-agent-development-1ra8od.md) · London (posted 2025-04-08) - [Enterprise Sales Engineer](https://aistartupslist.co.uk/company/sierra/enterprise-sales-engineer-uzmp7u.md) · London (posted 2026-06-02) - [Strategist, Agent Development](https://aistartupslist.co.uk/company/sierra/strategist-agent-development-17aru2.md) · London (posted 2025-06-12) - [Product Manager, Agent Development (French speaking)](https://aistartupslist.co.uk/company/sierra/product-manager-agent-development-french-speaking-jsqoa6.md) · London (posted 2025-08-21) - [Product Manager, Agent Development (Spanish speaking)](https://aistartupslist.co.uk/company/sierra/product-manager-agent-development-spanish-speaking-kof21m.md) · London (posted 2025-08-21) - [Recruiting Coordinator, Europe](https://aistartupslist.co.uk/company/sierra/recruiting-coordinator-europe-yvlxyx.md) · London (posted 2026-08-19) - [Software Engineer, Agent (German speaking)](https://aistartupslist.co.uk/company/sierra/software-engineer-agent-german-speaking-ex0135.md) · London (posted 2025-08-21) - [Software Engineer, Agent (French speaking)](https://aistartupslist.co.uk/company/sierra/software-engineer-agent-french-speaking-1y69bm.md) · London (posted 2025-08-21) - [Software Engineer, Agent (Spanish speaking)](https://aistartupslist.co.uk/company/sierra/software-engineer-agent-spanish-speaking-ugs7cc.md) · London (posted 2025-08-21) - [Enterprise Account Executive, Europe (Italian speaking)](https://aistartupslist.co.uk/company/sierra/enterprise-account-executive-europe-italian-speaking-1axod2.md) · London (posted 2025-12-04) - [Strategist, Agent Development (French speaking)](https://aistartupslist.co.uk/company/sierra/strategist-agent-development-french-speaking-yw0npi.md) · Paris (posted 2025-10-24) - [Strategist, Agent Development (Spanish speaking)](https://aistartupslist.co.uk/company/sierra/strategist-agent-development-spanish-speaking-hus7jc.md) · London (posted 2025-10-22) - [Strategist, Agent Development (French speaking)](https://aistartupslist.co.uk/company/sierra/strategist-agent-development-french-speaking-1i0s5o.md) · London (posted 2025-10-22) - [Software Engineer, Agent (Italian speaking)](https://aistartupslist.co.uk/company/sierra/software-engineer-agent-italian-speaking-1y4cem.md) · London (posted 2025-12-04) - [Product Manager, Agent Development (Arabic speaking)](https://aistartupslist.co.uk/company/sierra/product-manager-agent-development-arabic-speaking-1p7iqs.md) · London (posted 2025-12-04) - [Strategist, Agent Development (German speaking)](https://aistartupslist.co.uk/company/sierra/strategist-agent-development-german-speaking-1bu25x.md) · London (posted 2025-12-04) - [Strategist, Agent Development (Arabic speaking)](https://aistartupslist.co.uk/company/sierra/strategist-agent-development-arabic-speaking-dj17sf.md) · London (posted 2025-12-04) - [Product Manager, Agent Development (Italian speaking)](https://aistartupslist.co.uk/company/sierra/product-manager-agent-development-italian-speaking-1eit20.md) · London (posted 2025-12-04) - [Software Engineer, Agent (Arabic speaking)](https://aistartupslist.co.uk/company/sierra/software-engineer-agent-arabic-speaking-1l4klb.md) · London (posted 2025-12-04) - [Enterprise Account Executive, Europe (Arabic speaking)](https://aistartupslist.co.uk/company/sierra/enterprise-account-executive-europe-arabic-speaking-irlry4.md) · London (posted 2025-12-04) - [Strategist, Agent Development (Italian speaking)](https://aistartupslist.co.uk/company/sierra/strategist-agent-development-italian-speaking-yysyrh.md) · London (posted 2025-12-04) - [Software Engineer, Agent](https://aistartupslist.co.uk/company/sierra/software-engineer-agent-wgqb84.md) · Munich (posted 2025-12-16) - [Strategist, Agent Development](https://aistartupslist.co.uk/company/sierra/strategist-agent-development-1bn8m8.md) · Munich (posted 2025-12-16) - [Sales Director, DACH](https://aistartupslist.co.uk/company/sierra/sales-director-dach-hhys1a.md) · Munich (posted 2025-12-16) - [Technical Recruiter](https://aistartupslist.co.uk/company/sierra/technical-recruiter-i53ujy.md) · London (posted 2026-01-06) - [Business Recruiter](https://aistartupslist.co.uk/company/sierra/business-recruiter-14g7yf.md) · London (posted 2026-07-24) - [Engineering Manager, Agent](https://aistartupslist.co.uk/company/sierra/engineering-manager-agent-64138j.md) · London (posted 2026-02-27) - [Security and Compliance Manager](https://aistartupslist.co.uk/company/sierra/security-and-compliance-manager-61q11a.md) · London (posted 2026-03-13) - [Deployed Infrastructure Engineer (Spanish speaking)](https://aistartupslist.co.uk/company/sierra/deployed-infrastructure-engineer-spanish-speaking-jbm3d1.md) · London (posted 2026-08-11) - [AI Voice Designer](https://aistartupslist.co.uk/company/sierra/ai-voice-designer-rim73w.md) · London (posted 2026-05-05) - [Deal Operations Manager](https://aistartupslist.co.uk/company/sierra/deal-operations-manager-1ojuxm.md) · London (posted 2026-08-17) - [Software Engineer, Agent (Dutch speaking)](https://aistartupslist.co.uk/company/sierra/software-engineer-agent-dutch-speaking-w51i09.md) · London (posted 2026-06-10) - [Strategist, Agent Development (Dutch speaking)](https://aistartupslist.co.uk/company/sierra/strategist-agent-development-dutch-speaking-3ace02.md) · London (posted 2026-06-10) - [Deployed Infrastructure Engineer](https://aistartupslist.co.uk/company/sierra/deployed-infrastructure-engineer-oi501.md) · London (posted 2026-06-23) - [Pricing Strategy & Operations](https://aistartupslist.co.uk/company/sierra/pricing-strategy-and-operations-1m258e.md) · London (posted 2026-06-26) - [Brand Visual Designer](https://aistartupslist.co.uk/company/sierra/brand-visual-designer-1bsl9e.md) · London (posted 2026-07-03) - [Communications, Europe](https://aistartupslist.co.uk/company/sierra/communications-europe-1jme5u.md) · London (posted 2026-07-13) - [Enterprise Sales Leader](https://aistartupslist.co.uk/company/sierra/enterprise-sales-leader-188s0k.md) · London (posted 2026-08-12) - [Operations Manager, Product & Engineering](https://aistartupslist.co.uk/company/sierra/operations-manager-product-and-engineering-bt7qle.md) · London (posted 2026-08-10) - [Enterprise Sales Leader](https://aistartupslist.co.uk/company/sierra/enterprise-sales-leader-c2j94c.md) · Madrid (posted 2026-08-20) - [GTM Operations, Agent Development (London)](https://aistartupslist.co.uk/company/sierra/gtm-operations-agent-development-london-1f2014.md) · London (posted 2026-09-02)