Zhang's first job out of college was at a digital travel booking startup called Kuxun.

"I was one of first employees. And I was an ordinary engineer at the beginning, but in the second year, I was in charge of about 40 to 50 people responsible for back-end technology and other tasks related to products," Zhang told ByteDance employees, according to the South China Morning Post.

Zhang credits that job for teaching him sales skills that he later used to grow ByteDance.

"I remember that at the end of 2007, I went to meet the client with the sales director," Zhang said, according to the Post. "This experience let me know what sales are good sales. When I established Toutiao and recruited staff, these examples helped me a lot."

Zhang also worked at Microsoft before founding ByteDance, the South China Morning Post reported.