When Singaporean Shou Zi Chew became CEO of TikTok in May, the social media app was already a huge hit with teens for its short videos. In fact, it was the most downloaded app in 2020, a year when people sorely needed distraction from the COVID pandemic. Under Chew, TikTok is now looking to turn its popularity into profits. In August it partnered with Shopify to pilot shopping by letting select influencers on the app hawk products directly to users. The push into “social commerce” could be a windfall for TikTok. But the service faces challenges, too. The White House is reviewing the national security risks of foreign tech companies, including TikTok, which is owned by Beijing-based ByteDance. At the same time, China is cracking down on the data practices of its domestic tech companies. Chew, a 38-year-old Harvard Business School alum who is also the CFO of ByteDance, has the tough job of navigating the complex political scene of both China and the U.S.