OpenAI chief technology officer Mira Murati announced her resignation on Wednesday, a surprise change at the top of the influential AI company as it seeks to raise billions in new funding and undergoes a tumultuous transformation that has seen much of the old guard depart.

Murati, one of the most prominent female executives in the booming AI industry, said she was leaving OpenAI after more than six years at the company to “create the time and space to do my own exploration.”

Under Murati’s technical leadership, OpenAI sparked the generative AI era with the release of ChatGPT in November 2022. The company, which was originally created as a non-profit, has struck a $13 billion partnership with Microsoft and is currently in talks to raise funds in a deal that would reportedly value OpenAI at $150 billion.

Murati did not share details about where she’s heading next, and OpenAI has not announced who will serve as CTO in her absence.

In reply to Murati’s post, OpenAI CEO Sam Altman said the company will have more to say about the transition “soon.”

“It’s hard to overstate how much Mira has meant to OpenAI, our mission, and to us all personally,” he wrote.

Murati guided the company through a turbulent period in which was Altman was briefly ousted in a boardroom coup last year, before being reinstated five days later. Murati, who served as interim chief executive during that period, reportedly raised concerns about “a race to the bottom on safety” to the board but she ultimately supported rehiring Altman.

In the months since the failed coup, many of OpenAI’s early leaders have left, including cofounder Ilya Sutskever, as well as nearly half of the members of a key company AI safety team. Altman recently told OpenAI staffers that the company’s complex non-profit corporate structure is set to change, likely next year, Fortune previously reported.

In her goodbye note, posted to X, Murati thanked Altman cofounder Greg Brockman (who is currently on a leave of absence) “for their trust in me to lead the technical organization and for their support throughout the years.”

Murati’s departure comes as OpenAI touts recent releases of a speech-to-speech chat feature and its new landmark reasoning model, o1. Murati called these recent milestones “the beginning of a new era in interaction and intelligence.” OpenAi kicks off its annual DevDay in San Francisco next week.

A native of Albania, who grew up at a time when the Balkan country was undergoing a shift from totalitarianism to democracy, Murati worked at Tesla before joining OpenAI in 2018. In an interview with Fortune last year, Murati said she was drawn to OpenAI because of her interest in artificial general intelligence, or AGI.

“I wasn’t sure it was going to happen at that point, but I knew that even if we just got very close, the things we would build along the way would be incredible, and I thought it would definitely be the most important set of technologies that humanity has ever built,” Murati said in the interview.

Murati did not indicate when she would step down. In her goodbye note on Wednesday, she said she wanted to ensure a smooth transition and help maintain “the momentum we’ve built.”

OpenAI is currently seeking to raise $6.5 billion in funding from a group of backers that reportedly includes Josh Kushner’s Thrive Capital, Microsoft, Apple, and Nvidia.

“While I may no longer be in the trenches with you, I will still be rooting for you all,” Murati wrote.

I shared the following note with the OpenAI team today. pic.twitter.com/nsZ4khI06P