Five9 beat Wall Street expectations for the second quarter of 2026, with AI revenue accelerating to 78% year-over-year growth, prompting the company to raise its full-year AI outlook for the second time this year. The contact center software vendor reported Q2 revenue of $312.4 million, up 10% year-over-year and above the high end of its own guidance, while subscription revenue grew 14%, marking a third consecutive quarter of acceleration. AI revenue hit $39 million in Q2, an annual run rate of over $150 million, and now makes up 15% of subscription revenue, up from 9% a year ago. Five9 closed a Fortune 100 financial services deal worth roughly $100 million in total contract value, its first full-size win transacted through the Google Cloud Marketplace. CFO Bryan Lee told analysts AI revenue accelerated to 78% growth in Q2, up from 68% in Q1, pushing Five9 to raise its full-year AI growth outlook to "at least 60%" year-over-year. CEO Amit Mathradas used his second earnings call to argue that Five9's voice heritage separates it from point-solution competitors, noting contact centers are shifting from cost centers to growth levers. Three executive hires in Q2—a CTO, a Chief Sales Officer and an EVP of Transformation and Strategy—signal a shift from product-selling to platform-and-outcomes selling.