Meet Daniel Zhang, the workaholic who's succeeding Jack Ma as Alibaba's chairman and keeps such a low profile that he was once mistaken for a janitor in the company's headquarters

Zhang and Tsai met while Zhang was Shanda Interactive's chief financial officer in 2007, Bloomberg reported.

"Daniel really understands business," Tsai told Bloomberg of Zhang. "You can't disrupt unless you really understand what you're trying to disrupt."

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Before that, Zhang served as Alibaba's chief operating officer, according to his biography on Alibaba's website.

Ma originally appointed Jonathan Lu CEO after he himself vacated the position, but later decided that Alibaba would best be run by someone younger, Fortune reported.

"Teachers always want their students to exceed them," Ma wrote, according to a copy of the letter published by Quartz. "So the responsible thing to do for me and the company to do is to let younger, more talented people take over in leadership roles so that they inherit our mission 'to make it easy to do business anywhere.'"

Ma starred in a kung fu movie, sang at a music festival, and once performed at a company party while dressed as Michael Jackson, Business Insider previously reported.

Ma is also known for the extravagant events he holds for employees during Alibaba's annual Singles Day shopping event, whose sales last year quickly outstripped Amazon's Prime Day. The event has featured performers like Mariah Carey and Cirque du Soleil.

That's not to say that Zhang won't partake in Alibaba's famous company events. Zhang performed Josh Groban's "You Raise Me Up" alongside Ma at the former chairman's retirement party, the Wall Street Journal reported.

Zhang is not well-known in China like Ma is. Ma is so popular that his speaking engagements often draw large crowds, Business Insider previously reported.

Bloomberg described Zhang as "slight and soft-spoken, often proceeding haltingly in English during calls with investors."

"We believe that the best way to give thanks to yesterday is to create the most beautiful future together," Zhang said during his speech at Ma's retirement party.

Shares of Alibaba have lost 15% of their value since June of last year, Bloomberg reported. During Zhang's tenure as CEO before then, Alibaba's shares tripled, according to Bloomberg.

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"Every business has a life cycle," Zhang told Bloomberg. "If we don't kill our existing business, someone else will. So I'd rather see our own new businesses kill our existing business."

One new business Zhang supports is grocery and restaurant delivery service Freshippo, according to Bloomberg. Zhang worked on the project with a small team in a garage in Shanghai for months.

A normal weekday for Zhang "amounts pretty much to work, eat, and sleep," according to Bloomberg.

Alibaba has a reputation for requiring demanding hours and travel schedules from its employees, something employees poked fun at during their performances at Ma's retirement party September 10.

Zhang personally lobbied the online marketplaces' merchants to participate in the first Singles' Day in 2009, Bloomberg reported.

The event generated $25 billion in sales in 2018 and is bigger than Black Friday and Cyber Monday combined, Business Insider previously reported. Occurring every November 11, Singles Day is the world's largest day on online shopping.