Callum James Henderson-Begg
17 January 1981 (age 41)
|Occupation||computer programmer, author|
Henderson is best known as the co-founder and chief technology officer at Slack, as well as co-owning and developing the online creative community B3ta with Denise Wilton and Rob Manuel; being the chief software architect for the photo-sharing application Flickr (originally working for Ludicorp and then Yahoo); and writing the book Building Scalable Web Sites for O'Reilly Media.
He has also worked for EMAP as their technical director of special web projects and is responsible for writing City Creator among many other websites, services and desktop applications. Cal was the co-founder and VP of engineering at Tiny Speck, the company whose internal tool transitioned into Slack.
Henderson's connection to Stewart Butterfield and Slack began through a game developed by Butterfield's first company, Ludicorp, called Game Neverending. He ran a fan website dedicated to the game and broke into an internal Ludicorp mailing list. Instead of repercussions, Butterfield hired Henderson to work for his company.
Henderson is color blind, and has worked on applications to make the web more accessible to the color blind. He is also a frequent contributor to open-source software projects and runs a number of utility websites, such as Unicodey, to make certain programming tasks easier.
- "Cal Henderson is the co-founder of the San Francisco-based Tiny Speck". Sharnbrook Upper School. June 2014.[permanent dead link]
- "Slack co-founder Cal Henderson urges graduates to be their own boss". Birmingham City University. Retrieved 1 November 2017.
- "Interview with B3ta co-founder Rob Manuel". BBC. August 2005. Retrieved 12 June 2007.
- Forrest, Conner (13 April 2015). "Cal Henderson: Slack CTO. Author. Science fiction fan". TechRepublic.
- Honan, Mat. "The Most Fascinating Profile You'll Ever Read About a Guy and His Boring Startup". WIRED. Retrieved 4 May 2018.
- "The Team: Web Development Lead: Cal Henderson". Ludicorp. Archived from the original on 11 February 2004.
- "O'Reilly catalog - Building Scalable Web Sites". O'Reilly Media. Retrieved 12 June 2007.
- "Cal Henderson: Executive Profile & Biography - Bloomberg". www.bloomberg.com. Retrieved 4 May 2018.
- "City Creator - Yahoo! picks for September 16, 2003". Yahoo!. Archived from the original on 9 January 2007. Retrieved 12 June 2007.
- "Stewart Butterfield's Tiny Speck team". cnet.com. 9 February 2010.