On Monday, six years after taking over the reins of Twitter, he announced he was handing over.

"It was (a decision) hard to make, of course. I love this company so much, and all of you," he wrote in a letter to his 5.9 million subscribers.

"I'm very sad ... but also very happy. Few companies reach this level. And few founders choose their business over their ego," he continues, with a spike visibly addressed to Facebook, the one of the few tech giants still led by its founder, Mark Zuckerberg.

Mr. Dorsey's tenure was marked by the rise in problems of moderation of content on social networks, accused of promoting division and disinformation in democratic societies.

In early January 2021, the leader made an unprecedented decision: to ban Donald Trump - then followed by 88 million people - from Twitter for having encouraged the riots on Capitol Hill that killed several people.

But he then tweeted that he "felt no pride", and that the move was a "failure to promote healthy conversation" and set a "precedent" that he felt was "dangerous" for the power held by big business. .

A look that stands out

Jack Dorsey, who just turned 45, also runs Square, a digital payment service he co-founded in 2015. He will keep his seat on the Twitter board until the end of his term. in 2022.

He designed Twitter in 2006 with his sidekicks Noah Glass, Evan Williams and Biz Stone while working for the podcast platform Odeo, and has seen a meteoric rise in the tech world.

In the tradition of Steve Jobs, Mark Zuckerberg, Bill Gates or Michael Dell, this native of Saint-Louis (Missouri) stopped his studies before obtaining a university degree.

He learned computer programming on his own: before designing the Twitter program - in two weeks according to legend, with the German Florian Weber - he had created software to manage fleets of vehicles.

In the early days of Twitter, Mr. Dorsey sported a nose piercing and dreadlocks.

He later adopted a more streamlined style, usually hiding his forearm tattoo under the long sleeves of understated outfits, but keeping his long hipster beard.

Already ousted

His first stint at the head of Twitter between 2007 and 2008 went rather badly.

Criticized for his mismanagement, Mr. Dorsey ended up being replaced by Evan Williams.

However, he had retained an active role in the company, which entered Wall Street in November 2013, making him a billionaire in a matter of hours.

According to Forbes magazine, his personal fortune currently stands at $ 11.8 billion.

He owns 2.3% of Twitter's outstanding shares, but donated a third of his stake shortly after regaining the head of the group.

Mr. Dorsey was again CEO of the social network in July 2015. But his ability to juggle his responsibilities at Twitter and Square as well as his many side projects have questioned many investors in recent years.

The investment fund Elliott Management had notably sought to oust it in 2020.

- Massage and bitcoin -

His tastes are indeed very eclectic: he is a certified masseur, he took courses in botany and styling, and did not rule out in a 2013 interview on CBS from one day running for mayor of New York.

He is also a great believer in cryptocurrencies, in particular bitcoin, which he has described on various occasions as "the native currency of the internet".

In March, he sold his first tweet, which was the first ever post on Twitter, in the form of a non-fungible token (NFT) for a tidy sum of $ 2.9 million.

Childless, he resides in San Francisco (California), where the headquarters of Twitter and Square are almost next door on a major downtown thoroughfare.

As early as May 2020, he announced that employees could work from home indefinitely, even after the lifting of lockdowns linked to the pandemic.

© 2021 AFP