China has been a major sales driver for Tesla in recent times, thanks to the company’s aggressive price cuts. The country delivered 88,869 vehicles in March, according to fresh estimates from the China Passenger Car Association. That means more than half of the carmaker’s Q1 deliveries originated from its Shanghai factory.

It’s no surprise then that Tom Zhu, the executive behind Tesla’s rise in China, has quickly climbed through the company’s corporate ladder in recent years. Zhu began serving as the senior vice president of Tesla’s automotive unit in April, shows a new SEC filing. The appointment makes the executive one of the four most important faces at the electric vehicle powerhouse alongside CEO Elon Musk, CFO Zachary Kirkhorn and Andrew Baglino, SVP of powertrain and energy engineering.

According to the filing, Zhu joined Tesla in 2014 and served in various operational roles before being named vice president of Greater China, where he led the construction and operations of Gigafactory Shanghai. As the firm’s China production went into full swing, the 43-year-old executive was brought to Texas to run the new Gigafactory in Austin, Bloomberg reported in December.

The success of Tesla’s China factory didn’t come easily. Like Musk, Zhu is known for peaching a hardcore work ethic. During Shanghai’s COVID-19 lockdown, he slept in the factory with other workers to keep production running, according to a Reuters report.