Cal Henderson Speaking Fee: $200,000 to $300,000

Cal Henderson is a British-born technology executive and co-founder of Slack, the widely used workplace communication platform. He served as Slack’s Chief Technology Officer from its inception through its 2021 acquisition by Salesforce for $27.7 billion. In this role, Henderson led the company’s engineering, research, and design teams, setting the technical vision that helped Slack become a central hub for modern work. Henderson’s journey into tech began in his youth in Bedfordshire, England. At age 5, he was introduced to programming through the BASIC language on a cousin’s home computer. This sparked a lifelong passion for building software. After earning a degree in software engineering from Birmingham City University in 2002, Henderson moved to Vancouver, Canada. There, he joined Ludicorp, the company behind the online game Game Neverending. His deep engagement with the game led him to hack into the company's internal email system to suggest improvements, ultimately earning him a position as chief software architect. When Ludicorp pivoted to create Flickr, a photo-sharing platform, Henderson played a pivotal role in its development, which was later acquired by Yahoo in 2005. In 2009, Henderson reunited with Stewart Butterfield and other former Ludicorp colleagues to form Tiny Speck, aiming to develop a new video game. When that project, Glitch, did not succeed, the team repurposed their internal communication tool into what became Slack. Initially designed for small development teams, Slack quickly gained traction across various industries. Under Henderson’s leadership, the platform evolved into an indispensable tool for remote and hybrid work environments. Beyond his work at Slack, Henderson is a recognized figure in the tech community. He authored the best-selling O’Reilly Media book Building Scalable Websites and co-created foundational web technologies like OAuth and oEmbed, which are widely used across the internet. In 2019, he was named to Fortune’s “40 Under 40” list and recognized by the World Economic Forum as a Young Global Leader. He continues to advise and invest in emerging software companies while maintaining an active presence in the tech community.