Education - Zhang enrolled at Nankai University in Tianjin, where he majored in microelectronics before changing to software engineering, and graduated in 2005.
Early career - In February 2006, Zhang became the fifth employee and the first engineer at the travel website Kuxun, and was promoted to technical director a year later.
In 2008, Zhang left Kuxun to work for Microsoft, but felt stifled by the corporate rules of the company. He soon left Microsoft to join the startup Fanfou, which eventually failed.
In 2009, when Kuxun was about to be acquired by Expedia, Zhang took over Kuxun's real estate search business and started 99fang.com, his first company.
ByteDance - In 2011, Zhang noticed the user migration from computers to smartphones.
He hired a professional manager to take over as CEO of 99fang, and quit the company to start ByteDance in 2012.
TikTok - In September 2015, ByteDance launched its video sharing app TikTok (known as Douyin in China) with little fanfare.
The product was an instant hit with millennials and became popular worldwide.
ByteDance bought Musical.ly a year later for US$800 million and integrated it into TikTok.
Neihan Duanzi - ByteDance's first app, Neihan Duanzi, was shut down in 2018 by the National Radio and Television Administration.
In response, Zhang issued an apology stating that the app was "incommensurate with socialist core values", and promised that ByteDance would "further deepen cooperation" with the ruling Communist Party of China to better promote its policies.
Net worth - As of late 2018, with more than 1 billion monthly users across its mobile apps, ByteDance is valued at US$75 billion, surpassing Uber to become the most valuable startup in the world.
Zhang's personal wealth is estimated at $16.2 billion, making him the 9th richest person in China.
Honors - Zhang was named in the 2013 China 30 Under 30 list by Forbes.
In 2018, he was included in Fortune magazine's 40 Under 40 list.
Personal life - He met his future wife while studying in college.
Bio / wiki sources: Wikipedia, accounts on social media, content from our users.