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About [ on iamcal.com ]

About Cal Henderson


Cal Henderson is the Co-founder and CTO of Slack. He has been working as a web applications developer for more than 15 years.

Slack was previously Tiny Speck, creators of the massively multiplayer online game Glitch. Prior to his work at Tiny Speck, Cal was Flickr's Director of Engineering at Yahoo!. He was an inaugural member of the groundbreaking photo-sharing site, working alongside Flickr co-founder Stewart Butterfield, the now CEO and Co-Founder of Slack.

In 2006, Cal wrote the best-selling book Building Scalable Websites, and is currently working on a second edition. In his spare time he continues to publish articles on web application development and contribute to open source projects.

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About iamcal.com

iamcal.com has been online for 19 years, 44 days, 17 hours, 28 minutes and 52 seconds - crumbs!

iamcal.com is primarily cal henderson's personal site, containing his linklog/weblog which he's been posting to regularly since June 2000:

It also hosts a discussion forum where anyone can signup and post. The topic is roughly "whatever". more »

An incomplete list of other sites that Cal has created or been involved with can be found on the network homepage.


Please do not contact me at my personal address regarding Slack. Instead, use pr@slack.com for press or speaking enquiries, or feedback@slack.com for any other issues.