Shou Zi Chew may be the CEO of Mark Zuckerberg’s biggest competitor, TikTok, but at the start of his career, he worked for Zuckerberg as an intern at Facebook.

The Singapore native earned an economics degree from University College London before getting his MBA at Harvard Business School, where during the summer he interned at an up-and-coming company: “It was called Facebook,” Chew told Harvard’s Business School alumni website.

Soon after he kicked off his tech career at Facebook in California, he moved abroad, stopping in London, Singapore, and Hong Kong, before ultimately landing in Beijing. Chew joined Chinese tech company Xiaomi in 2015, helping take the company public three years later as chief financial officer, according to the Harvard Business School alumni website.

Then in 2021, Chew’s career once again crossed paths with Meta CEO Zuckerberg, this time as a competitor. Chew joined TikTok parent company ByteDance in 2021, first as CFO. Later that year, he became CEO of TikTok, and held both the CFO position at ByteDance and the CEO position at TikTok before ultimately focusing on the short-form video platform.

With at least 150 million monthly active users in the U.S. and more than 1 billion globally, TikTok has become a mainstay of social media and a rare top platform that is not under the control of Zuckerberg. But just because he doesn’t own it, doesn’t mean he never tried.

Zuckerberg reportedly spent much of 2016 trying to acquire a key part of what would become TikTok—a lip syncing app popular with Americans called Musical.ly, Buzzfeed News reported. Yet, Zuckerberg lost out to ByteDance, which acquired the app for $800 million in 2017. ByteDance merged Musical.ly with the already existing TikTok platform, and the resulting social network took off.

Meta tried to launch its own competitor to TikTok called Lasso in 2018, but it never caught on. Meta shut down the copycat app in 2020.

As efforts to ban TikTok from the U.S. have ramped up over the past few years, so have Zuckerberg’s criticisms of the app. Now, an emerging TikTok deal with China would ensure U.S. companies control the algorithm powering the app’s video feed and Americans will hold a majority of seats on a board overseeing U.S. operations. Zuckerberg has previously suggested TikTok could be a threat to global free expression on social media. In 2020, he said banning the app could set a bad precedent, but added he also sympathized with the national-security concerns.

“I certainly think that there are valid national security questions about having an app that has a lot of people’s data that follows the rules of another country, a government that is increasingly is kind of seen as a competitor,” Zuckerberg said in an internal meeting in 2020, according to BuzzFeed News.

Chew has, in previous Congressional hearings, defended TikTok against accusations that it is a national-security threat. In a hearing before the House Energy and Commerce Committee in 2023, Chew took a dig at Facebook’s Cambridge Analytica scandal, and said TikTok didn’t collect more data than American social-media platforms.

“I don’t think ownership is the issue here,” he said during the hearing. “American social companies don’t have a good track record with data privacy and user security.” (YAHOO)