Jack Patrick Dorsey is an American web developer and entrepreneur, the self-made billionaire co-founder of Twitter (now X) and Block, Inc. (formerly Square). Born in St. Louis, Missouri, in 1976, his early interest was in dispatch routing (creating taxi-dispatching software as a teenager that was adopted by taxicab companies).

Dorsey attended the University of Missouri–Rolla before transferring to New York University (NYU), but he dropped out one semester short of graduating. His career began with work in dispatch programming in California. His philosophical principles are simplicity, constraint, and craftsmanship (the guiding philosophy of his companies).

• Twitter / X (Co-founder & Former CEO): The microblogging platform. He served as CEO from 2007–2008 and 2015–2021.
• Block, Inc. (Co-founder & CEO): The financial services and mobile payments platform (formerly Square).
• Early Venture: He created taxi-dispatching software as a teenager.
• Bitcoin Advocate: He is one of the world's most vocal proponents of Bitcoin, advocating for its widespread adoption and development.

Jack Dorsey co-founded Twitter, Inc. in 2006 (with Evan Williams and Biz Stone), based on his idea for a Web-based real-time status/short message communication service (inspired by LiveJournal and AOL Instant Messenger). He became CEO in 2007 and, after a period away, returned as CEO from 2015 to 2021, guiding the company through its immense global growth and public scrutiny.

His structural financial move was co-founding Square (now Block, Inc.) in 2010, a major force in financial services and mobile payments that provided critical infrastructure for small businesses. Dorsey now serves as CEO of Block, Inc. and has focused his entrepreneurial drive entirely on decentralization and Bitcoin development (founding Bluesky and committing resources to Bitcoin development). His wealth is tied to his massive equity stakes in both publicly traded giants.

Jack Dorsey's social impact is massive and structural, tied to Twitter's role in shaping global communication, political discourse, and citizen journalism. Block's payment platform provided essential financial inclusion for small businesses and merchants. His personal philanthropy is immense, often channeled through a pledge to give away most of his wealth to social and community causes.

His structural contribution is tied to his advocacy for decentralization, censorship resistance, and Bitcoin development, influencing the next generation of internet architecture and digital finance.

Jack Dorsey maintains a distinctive, minimalist, and often eccentric style. His attire is consistently simple (jeans, dark shirts), reflecting his commitment to simplicity, constraint, and craftsmanship. His aesthetic is one of deliberate focus and technological austerity.

Residing in San Francisco, California, his luxury is the immense security and financial reward derived from his multi-billion dollar fortune. His life is dedicated to technology innovation, decentralization, and his profound, structural commitment to Bitcoin and digital financial services.