Five9 provides cloud-based contact center software, known as CCaaS (Contact Center as a Service), to enterprise customers. Contact centers are hubs where companies handle customer interactions — phone calls, chats, emails, and texts — for customer service, sales, or marketing. Five9's platform routes interactions to the right agent or AI agent, gives agents real-time customer data, and provides supervisors with analytics and workforce tools. Five9 serves over 3,000 customers across financial services, healthcare, retail, and technology, ranging from smaller businesses to Fortune 1000 enterprises. Revenue breaks into three streams: subscription (~82%), telecom usage (~11%), and professional services (~7%). Five9 is deliberately shifting mix toward subscription and away from the lower-margin telecom and services revenue. Within subscription, Five9 offers its core CCaaS platform plus its Genius AI suite — including AI Agents (virtual agents handling calls autonomously) and Agent Assist (real-time guidance for human agents) — which crossed $100M in annualized revenue and represents ~12% of enterprise subscription revenue. Core CCaaS is priced per agent seat; AI products layer on consumption-based pricing that scales with usage, creating a natural upsell path. Five9 targets the upper end of the enterprise market, where large seat counts and ongoing migrations from on-premises systems drive growth. More than 80% of business runs through partners, including system integrators like Accenture and Deloitte, CRM vendors like Salesforce and ServiceNow, and telecom resellers.