TikTok, the upstart social media app, has opened an office in Silicon Valley and begun to poach Facebook employees, multiple people familiar with the matter told CNBC. The Chinese-owned company recently moved into an office space in Mountain View, California, that was previously occupied by Facebook's WhatsApp messaging app, multiple people told CNBC. The new location gives TikTok a presence just miles from the Menlo Park headquarters of Facebook, elevating the rivalry between the two companies from a battle for young users to a competition for talent. TikTok was released in 2017 by China-based company ByteDance, which makes a Chinese version of the app called Douyin. TikTok lets users watch and create short videos that are usually set to songs. Across its suite of apps and around the globe, ByteDance now claims 700 million daily active users. By way of comparison, Facebook claims more than 2.1 billion people use one of its apps, including Instagram, Messenger or WhatsApp, every day. Along with the new office, TikTok and ByteDance have posted numerous job listings for positions in the San Francisco Bay Area, according to LinkedIn. Since 2018, the company has hired more than two dozen employees from Facebook.

The appeal to leave Facebook for TikTok stems from a desire to work at a popular social media company as it goes through an extreme growth phase, two former Facebook employees who are now at TikTok told CNBC. Although Facebook offers unrivaled perks, such as free food throughout the day, TikTok is offering salaries that are comparable and competitive to that of its rival. One person said TikTok has been known to offer salaries that are as much as 20% higher than Facebook's. TikTok is interested in hiring employees with experience from competitors who have the ability to fix issues that arise with high-growth technology, one person said. As it's been poaching from Facebook, TikTok has hired even more people from other tech companies, including Snap, Hulu, Apple, Google's YouTube and Amazon, according to another person familiar. These people asked for anonymity when discussing confidential business matters. Besides its new Bay Area office, TikTok is also planning to upgrade its headquarters in Culver City, California, near Los Angeles. The company will move into a new office there in early 2020 with the capacity for 1,000 employees, a person familiar with the company's plans told CNBC. Facebook has yet to list TikTok as a competitor on its financial documents as Twitter and Snap have both done, but the company has landed on its radar nonetheless.