Bill Pugliano/Getty Images
Although Dorsey said he planned to run both companies simultaneous, one theory was that he was actually gunning for the Twitter CEO spot and would end up leaving Square.
But, Dorsey firmly rebuked that narrative to Re/code, insisting that he'll be maintaining his role at the payments company.
Meaning that from July 1, when he starts, until whenever Twitter finds another permanent candidate, he'll be running both companies.
Although that task is made a little easier by the fact that Square and Twitter are located just a few blocks away from each other and Dorsey has said in the past that he already spends a ton of time at both, it's still an enormous job to manage two multi-billion-dollar companies at once.
As he takes on new responsibilities at Twitter, Dorsey will depend on his bench of executives to pick up the slack. Although a person close to the company told Business Insider that there is "absolutely not" any current employee who could take over if Dorsey did decide to leave, Square does have an impressive line-up of people who have come from other major tech companies like Apple, Amazon, and Google (especially Google).
Who are those they?
Here's the team who Dorsey will be relying on more than ever:
Friar joined Square from Salesforce, where she was a top strategy and finance executive. Before that, she worked as an analyst at Goldman - which could be especially valuable since Square reportedly plans to go public this year.
Gokul Rajaram, Product lead for Caviar
It was a big loss for Facebook when Rajaram, who was in charge of developing new ad units, ditched for Square in June 2013. At Square, he's a product engineering lead, and focuses in large part on Caviar, the San Francisco-based food delivery startup Square bought for a reported $90 million last summer. Caviar is one of the startup's biggest efforts to diversify its line-up of products and services.
Before Facebook, Rajaram spent five years at Google, where his last job was Product Management Director, AdSense. He was also a product lead for several Google acquisitions and has been described by past colleagues as "a legend" and "beloved times ten."
Jesse Dorogusker, Hardware lead
Dorogusker has been leading hardware at Square for nearly four years, after spending the previous eight at Apple, most recently as director of engineering of iPod, iPhone, and iPad accessories. He's responsible for physical products like Square's signature card reader.
An early investor tells Business Insider that before Rajaram came in, he was essentially running all of product.
Francoise Brougher, Business
Brougher has a huge job at Square: as the business lead, she's responsible its international expansion, customer service, partnerships, and making sure that its products actually make money.
Before Square, she was a long-time Google vet, as VP of small business global sales and operations.
Brian Grassadonia, Product lead, Square Cash
Grassadonia joined Square as its first product manager nearly five years ago, and now focuses on the startup's consumer money transfer product, Square Cash. Since Square Cash first launched in 2013, it has processed over $1 billion annually and most recently introduced a way for businesses to accept payments through "$Cashtags."
LinkedIn
Henry runs the product and engineering teams for everything Square makes for businesses, including Square Capital and Square Register. The company poached her from Amazon in 2014, where she was VP of its web services business, AWS.
Dana Wagner, General Counsel
Before coming to Square, Wagner was the public face of Google as it faced increased regulatory scrutiny, as its senior competition counsel.
A few years ago, Fortune named him one of tech's five most powerful lawyers, in part because of his role helping Square navigate government regulations.
Adi Roy, People
Roy heads up recruiting, human resources, and diversity initiatives at Square as its head of people, as of earlier this month. Before Square, he was at Google for nearly 10 years. His recent hire suggests that the company, which already has more than 1,000 employees, is looking ot bulk up even more.
Aaron Zamost, Communications
Formerly at Google for about four years, Zamost now leads Square's communications teams, no small job right now as the startup gets more attention than usual thanks to Dorsey's non-traditional dual-CEO-ship.