This 27-year-old from London built a $7.8-billion business after a rare allergic reaction

The 27-year-old is now among the world's youngest self-made billionaires at $3.2 billion, according to the Bloomberg Billionaires Index.

When first released, Hopin allowed users to attend break-out sessions during events and network with attendees through automated one-on-one video meetings. Though Boufarhat had initially planned to launch Hopin in September 2020, the pandemic forced him to speed up his release date by six months and catapulted his fortunes, with people shifting to online meetings after lockdowns were announced.

Hopin has come a long way. They now employ 800 people, up from the six in 2020, have bought out video tech companies like StreamYard, Streamable and Jamm. In June, they acquired Boomset, a management platform for in-person and hybrid events and in July, they acquired event marketing company, Attendify.

He has an incredible passion for business and a clear vision, said Tom Wilson of Seedcamp, who led Hopin’s 2019 pre-seed investment round to Bloomberg.

"Johnny had it figured out long before the pandemic," said Par-Jorgen Parson, general partner, Northzone. Northzone is a London-based venture capital firm and one of Hopin’s backers.

According to Bloomberg’s Billionaire index, there are 19 billionaires under the age of 40 in the world’s 500 richest list and Boufarhat is the latest to join the club. He joins the likes of Patrick and John Collision, who founded online payment company Stripe; Nikolay Storonsky, founder of Revolut and Luminar Technologies; and Austin Russel, who is all of 26 years.