10th co-founder to leave xAI

Bussiness Insider Citing an internal source, Kroiss, known by his nickname Makro, informed employees about leaving the company. Currently xAI and Kroiss have not commented.

Musk founded xAI on July 12, 2023 with 12 members. Musk’s 11 subordinate directors are all experts in the field of artificial intelligence, having worked for Google, Microsoft and Tesla. However, in less than three years, the number “dropped” gradually, such as Kyle Kosic joining OpenAI in mid-2024, Christian Szegedy quit in February 2025, then Igor Babuschkin resigned in August of the same year to establish a venture capital company. Since the beginning of 2026, there have been 7 more people quitting their jobs, including Guodong Zhang, Zihang Dai, Toby Pohlen, Jimmy Ba, Tony Wu, Greg Yang and most recently Kross.

At xAI, Kroiss is in charge of preliminary training, helping train AI models on large data sets and reporting directly to Musk. He participated in improving xAI’s programming models along with Zhang, who quit in early March. At the Abundance360 summit in the US in early March, Musk admitted that xAI was “lagging behind in programming”, but was working to “outperform competitors”.

Before joining xAI, Kroiss worked at Google DeepMind. He is quite secretive, with almost no photos or information on the Internet, except for account X with the most recent post in November 2025.

Among the founding members, only Ross Nordeen, who joined xAI from Tesla, remains with Musk. Some sources say the company’s organizational structure has been changing in the past few weeks, after xAI merged with SpaceX in February. Musk took over the direct management of dozens of subordinate employees, transferred personnel from Tesla and SpaceX, as well as laid off a number of other departments.

In early March, Musk wrote on X that xAI was “not built right from the beginning, so is being rebuilt from the ground up.” In another post, the American billionaire said the company is screening employees to recruit new employees.