Cal Henderson Email Address

Chief Technology Officer

Slack is a team communication application providing services such as real-time messaging, archiving, and to search for modern teams. It offers one-on-one messaging, private groups, persistent chat rooms, and direct messaging as well as group chats organized by topic.

I am the Co-founder & CTO at Slack, a new platform for team communication, in San Francisco, California. Previously, Co-founder and VP Eng for Glitch, a web-based massively multiplayer game. Before that, the Director of Engineering for Flickr at Ludicorp and then Yahoo! Back in the UK, I was the technical director of Special Web Projects at Emap, a UK media company and co-created the creative community B3TA. In 2006 I wrote the best selling book Building Scalable Websites. I promise I'm working on a second edition.