At the age of 39 Jack Dorsey is already being lauded as one of the world's best entrepreneurs.
He's the chief executive and co-founder of social media network Twitter and payment technology business Square and is in Australia for the first time. 
Dorsey has come straight off the plane to Five & Dime Bagel in Melbourne, a small business which has just installed Square's payment system. The billionaire is hard to spot amongst the bagel store's other customers with his hipster beard and all black attire of leather jacket and undone biker boots.
But he runs two of the world's biggest tech players with a combined market capitalisation of US$16 billion.
Dorsey says both his parents were entrepreneurs, running a pizza shop and a coffee store, and he learnt from them.
"To me being an entrepreneur is just taking a risk, doing whatever is necessary to make it work," he says. "I've always had that edge I guess and that desire."
That desire translates to 15 to 18-hour work days for Dorsey as he juggles his role at the companies.
"I guess I focus my time on what is most meaningful, some weeks require a lot more than other weeks, some days require a lot more than other days," he says.
"The best use of my time is building a team and recruiting and making sure we get along as a team. We have ups and downs."
Twitter and Square's offices are across the street from each other in San Francisco and Dorsey spends his time running between the two, saying he thrives on the workload.
Square's business is driven by the Square Reader, a small piece of plastic that plugs into any smartphone or tablet and turns it into a credit card processor.
"The biggest part is speed, how quickly someone can start accepting credit cards, how quickly someone can start growing their business. We're solving a real problem," he says.
Dorsey has previously described payments as "magical" but today settles on "sexy".
"It all comes back eventually to a payment if you are buying art, you are buying music, you are buying food," he says.
"It enables a bunch of different activities that people want to do. It's fundamental."
In the future Dorsey believes payments will take even less time for consumers and businesses.
"Paper cash, paper receipts and paper cheques are diminishing. Everything is going more and more digital."He hopes to replicate Square's growth in Australia and is undeterred by competition from banks or local providers like Tyro.
"I don't believe it is important to be the first in the market, I believe it is important to be the best.
"We want to continue winning the hearts of small business here."