Jimmy Barr, one of the co-founders of Elon Musk’s AI startup xAI, said he is stepping down. He shared news about X, reflected on his time there, and thanked Musk for pulling together the early staff. He also expressed his gratitude to his teammates. For Ba, people were more important than what the company shipped.In his farewell post, he made it clear that xAI is not just about code and big ideas. It was late at night. Back and forth. Small victories that only the team notices. And even if he wants to leave, he says he won’t disappear. He will continue to keep in touch and support them from the outside.So what’s next? Ba hinted that technology is currently advancing at an incredible pace. Tools are improving rapidly and will change the way people work. He believes the year ahead could be tough for AI. busy. Messy. And it’s sort of a big question as to where all this is going.But it was the timing that caught people’s attention. His departure comes just two days after xAI’s other co-founder, Tony Wu, announced he was also stepping down. Two founders working together back to back. This sparked a lot of discussion online, with people wondering what was going on inside Musk’s AI shop.
Who is Jimmy Barr?
Ba is a Canadian machine learning researcher and professor at the University of Toronto. He completed his PhD in 2018 with Jeffrey Hinton, one of the leading figures in the field. In 2023, he worked with Musk and a small group of researchers to help launch xAI, which builds advanced AI systems.
How have people reacted online?
The reply came quickly. Some people were curious. Why do so many founders leave so soon? Some were more personal. Teammates and those who worked with Ba thanked him, calling him a steadying presence and wishing him well in his future endeavors.
How many co-founders of xAI remain?
With Ba gone, six of the original 12 co-founders have left. Over the past few years, several major names have left the company for various reasons. Kyle Kosick left the company in 2024 to join OpenAI. Christian Szegedi’s term ends in 2025. Igor Babushkin left his job to start a venture company. Greg Yang resigned in January 2026, citing health issues. And earlier this week, Tony Woo said he was starting a new chapter. Then followed Ba.Indeed, this is a big change for a young company.
