British software engineer, 38, to make £500m when his tech firm makes its debut on the US stock market
A British software engineer stands to get nearly £450million when his tech company makes its long-awaited debut on the US stock market.
Cal Henderson co-founded workplace messaging service Slack with Stewart Butterfield, and their business could be valued at £13billion when it lists in New York.
It means Henderson, 38, who owns around 3.4 per cent of the company, could have a stake worth as much as £447million.
Windfall: Cal Henderson co-founded workplace messaging service Slack with Stewart Butterfield, and their business could be valued at £13billion when it lists in New York
He is a computer science graduate of Birmingham City University but has lived in North America since 2003.
He got his first job across the Atlantic at IT firm Ludicorp, after hacking into the email system of the company and telling its bosses that he could help them fix the problems they were grappling with.
There, Henderson met Butterfield, a founder at Ludicorp, and the pair went on to set-up photo-sharing website Flickr.
Flickr was later sold to tech giant Yahoo for more than £19million in 2005, making Henderson one of Silicon Valley’s most successful entrepreneurs at the age of just 24.
With other former Flickr staff and Butterfield, Henderson founded Slack in 2009. They created the messaging service as a replacement for email, which they say creates ‘fragmented silos of inaccessible information, hidden in individual inboxes’.
Henderson is Slack’s chief technology officer. The father-of-two, who grew up in Bedfordshire, is also an author who has published a best-selling book on building websites.
Slack is among a wave of hotly-anticipated tech companies going public this year, following in the footsteps of taxi firms Lyft and Uber, video service Zoom and digital scrapbook website Pinterest.