Jack Dorsey

Dorsey grew up in St. Louis fascinated by dispatch systems — the routing of taxis, couriers, ambulances — and was writing dispatch software as a teenager. He studied briefly at the University of Missouri-Rolla before transferring to New York University, where he began sketching a "web-based realtime status" messaging idea inspired by AOL Instant Messenger and LiveJournal, and left one semester short of a degree. He moved to the Bay Area and ran a small dispatch-routing company before landing at a struggling podcasting startup called Odeo, where, in about two weeks in 2006, he and colleague Biz Stone built a working prototype of what became Twitter.

Twitter, Inc. incorporated in 2007 with Dorsey as CEO; the board pushed him out in October 2008, reportedly over his part-time attention to the job, and he stayed on as chairman. In 2009 he co-founded Square with Jim McKelvey to let small merchants take card payments on a phone, taking it public in 2015. That same year he returned to Twitter, first as interim and then permanent CEO, running both public companies at once — an arrangement that drew sustained shareholder criticism before he resigned from Twitter in November 2021. He renamed Square to Block weeks later, folding in Cash App and a growing set of Bitcoin ventures, and by 2026 remained Block's CEO, having cut its workforce by roughly half early that year in an AI-driven restructuring.

Dorsey built Twitter's early moderation policy around a "world leader exception" that let Donald Trump's posts stand through years of norm-breaking, then banned him permanently after the January 6, 2021 Capitol attack — a decision Dorsey later called right but "a precedent I feel is dangerous." After Elon Musk bought Twitter in 2022, Dorsey went further, saying the company should never have existed as a centralized corporation at all, an unusual public renunciation of the platform he spent fifteen years building and running. He has since backed Bitcoin infrastructure, a peer-to-peer messaging app, and a revival of the defunct video app Vine, while also presiding over Block's deepest-ever layoffs — a founder known for an employee-friendly reputation now cutting the company he still runs in half.

The platform Dorsey is best known for building no longer exists in the form he left it — Twitter became X under different ownership and a different moderation philosophy soon after his departure — which leaves an odd gap where a legacy would normally sit. He has moved through payments, social media, Bitcoin evangelism, a brief and openly disillusioned stint on the board of a decentralized Twitter alternative, and now an AI-driven overhaul of Block, without settling into one identity long enough for a clear verdict to form. Whether the throughline is genuine invention or restlessness dressed as principle is a question 2026 has not answered, and Dorsey does not seem interested in answering it.

Jack Dorsey's life against the full span of the corpus — the fading end marks a life still in progress.

• Twitter company
  Co-founded with Biz Stone and Evan Williams 2006
• Square company
  Co-founded with Jim McKelvey; renamed Block in 2021 2009
• Cash App invention
  Peer-to-peer payment product now central to Block's business 2013
• Bitkey invention
  Hardware Bitcoin wallet developed at Block 2023
• Bitchat invention
  Peer-to-peer Bluetooth messaging app requiring no internet or server 2025

• November 19, 1976 aged 0 Born in St. Louis, Missouri
• 1997 aged ~21 Transfers to New York University after two years at Missouri-Rolla He left one semester short of a degree.
• 2006 aged ~30 Builds a working Twitter prototype with Biz Stone in about two weeks
• October 2008 aged 31 Ousted as Twitter's CEO by its board, becomes chairman
• 2009 aged ~33 Co-founds Square with Jim McKelvey
• October 2015 aged 38 Named permanent CEO of Twitter while remaining CEO of Square
• November 29, 2021 aged 45 Resigns as Twitter's CEO
• December 2021 aged 45 Renames Square to Block
• February 2026 aged 49 Cuts Block's workforce by roughly half, citing an AI-driven restructuring

• Elon Musk b. 1971
  Engineer and entrepreneur whose companies have advanced electric vehicles, reusable rockets, and neural interfaces. sold Twitter shares into the buyout by
• Jay-Z b. 1969
  Rapper and entrepreneur whose career helped move hip-hop from a subculture to the center of American business and culture. partnered with
• Donald Trump b. 1946
  Businessman, media personality, and 45th and 47th president whose populist movement transformed American politics. banned
• Jamie Dimon b. 1956
  Bank executive whose leadership of JPMorgan Chase made him one of the most influential voices in American finance. disrupted the industry of