Dorsey, who also helms fintech firm Square Inc, will be succeeded by Chief Technology Officer Parag Agrawal.
Here is a timeline of milestones in Dorsey tenure at Twitter:
2006 https://twitter.com/jack/status/20?s=20: Typed out the microblogging platform's first post: "just setting up my twttr".
2008 https://www.reuters.com/article/twitter-ceo-idUSN1642880520081016: Co-founder Evan Williams took over as CEO after the board pushed Dorsey out. Dorsey assumed the role of chairman.
2013 https://www.reuters.com/article/us-twitter-ipo-idUSBRE99N1AE20131107: Twitter went public at a valuation of $31 billion.
2015 https://www.reuters.com/article/us-twitter-ceo-dorsey-idUSKCN0RZ16520151005: Dorsey returned as CEO after Dick Costolo stepped down.
2017 https://www.reuters.com/article/us-usa-trump-idUSKBN1D3015: A Twitter employee on his last day deactivated then U.S. President Donald Trump's account which was restored 11 minutes later.
2018 https://www.reuters.com/article/us-twitter-character-idUSKBN1D72ZB: Twitter increased the character limit of tweets to 280 from 140, sparking a mixed reaction in twitterverse.
2020 https://www.reuters.com/article/us-softbank-group-stake-elliott-idUSKBN2002PW?taid=5e3cecabebed6f0001a5a00d&utm: Activist hedge fund Elliott Management pushed for changes, including the removal of Dorsey as CEO.
2020 https://www.reuters.com/article/us-twitter-elliott-idUSKBN20W1SS: Twitter reached an agreement with Elliott to add three new directors for letting Dorsey stay on as CEO.
2021 https://www.reuters.com/world/us/twitter-permanently-suspends-trumps-account-cites-incitement-violence-risk-2021-01-09: In the wake of the riots at the Capitol, Twitter permanently suspended Trump's account, with the company citing a risk of further incitement of violence.
2021 https://www.reuters.com/article/us-twitter-outlook-idUSKBN2AP1WD: Twitter outlined plans in February to attain at least $7.5 billion in annual revenue and 315 million monetizable daily active users, or those who see ads, by the end of 2023.
2021 https://www.reuters.com/business/media-telecom/twitter-boss-jack-dorseys-first-tweet-sold-29-million-an-nft-2021-03-22: In March, Dorsey sold his first tweet as a non-fungible token (NFT) - a kind of unique digital asset - for just over $2.9 million.
2021 https://www.reuters.com/world/us/trump-says-he-is-suing-facebook-twitter-google-claiming-bias-2021-07-07: Former U.S. President Donald Trump in July filed lawsuits against Twitter, Facebook Inc and Alphabet Inc's Google, as well as their chief executives, alleging they unlawfully silence conservative viewpoints.
2021 https://www.sec.gov/Archives/edgar/data/0001418091/000141809121000209/twtr-20210930.htm: The company said it had 211 million average monetizable daily active users, as of the three months ended Sept. 30.
2021 https://www.forbes.com/profile/jack-dorsey/?sh=550e82942372: Dorsey's net worth is $11.8 billion as of Nov. 29, according to Forbes.
(Reporting by Akash Sriram and Chavi Mehta in Bengaluru; Editing by Sriraj Kalluvila)