TMTPOST--OpenAI co-founder John Schulman announced in a Monday X post that he would leave the Microsoft-backed company to join Anthropic, a rival artificial intelligence (AI) startup funded by Amazon.

Greg Brockman, another co-founder of OpenAI and its president, also announced on Monday that he would take a sabbatical for the rest of the year.

This transition occurs less than three months after OpenAI disbanded its superalignment team, which aimed to ensure AI systems surpassing human capabilities could be controlled by people.

Peter Deng, the vice president of product, also left the company in recent months. And earlier this year, several members of the company’s safety teams exited.

Ilya Sutskever, another one of OpenAI’s co-founders and chief scientist, left the company in May. Andrej Karpathy, who was also one of the AI firm’s founding members, left in February and started an AI-integrated education platform in July.

Schulman was a co-leader of OpenAI's post-training team, responsible for refining AI models for the ChatGPT chatbot and a programming interface for third-party developers, according to his website biography.

In June, OpenAI announced that Schulman, as head of alignment science, would join a safety and security committee to advise the board. Schulman had been with OpenAI since earning his Ph.D. in computer science from the University of California, Berkeley, in 2016.

"This choice stems from my desire to deepen my focus on AI alignment and start a new chapter of my career where I can return to hands-on technical work," Schulman wrote in the social media post on X.

He clarified that his departure was not due to a lack of support for AI alignment at OpenAI. "On the contrary, company leaders have been very committed to investing in this area," he said.

Jan Leike and Ilya Sutskever, leaders of the former superalignment team, both left OpenAI this year. Leike joined Anthropic, while Sutskever said he was starting a new company, Safe Superintelligence Inc.

Since its establishment by former OpenAI staff in 2021, Anthropic has been competing with OpenAI to develop the most advanced generative AI models capable of producing human-like text. Amazon, Google, and Meta have also developed large language models.

"Very excited to be working together again!" Leike wrote in response to Schulman's message.

Sam Altman, OpenAI's co-founder and CEO, noted in his own post that Schulman's insights had shaped the startup's early strategy.

Schulman and others chose to leave after the board ousted Altman as CEO last November. Employee protests led to the resignations of Sutskever and two other board members, Tasha McCauley and Helen Toner. Altman was reinstated, and OpenAI added new board members.

Toner mentioned on a podcast that Altman had provided the board with incorrect information regarding the company's limited formal safety processes.

An independent review by law firm WilmerHale found that the board was not concerned about product safety when it removed Altman.

Last week, Altman said on X that OpenAI "has been working with the U.S. AI Safety Institute on an agreement to provide early access to our next foundation model to advance the science of AI evaluations." He affirmed that OpenAI remains committed to dedicating 20% of its computing resources to safety initiatives.

The leadership changes come shortly after reports that Microsoft and Apple withdrew their bids for board seats at OpenAI amidst increasing antitrust scrutiny of the company and its partners.

Tesla CEO Elon Musk, who was also one of the co-founders of OpenAI and left three years later, refiled his lawsuit against the company and CEO Sam Altman on Monday, claiming that the firm put profits and commercial interests above the public good.