Sam Altman has officially resumed his role as CEO of OpenAI, marking his return with a memo outlining changes to the company’s board. Notably, Microsoft, a primary investor in OpenAI, has secured a non-voting observer seat on the board.

Microsoft holds a substantial 49% stake in the for-profit entity controlled by the nonprofit board. This move solidifies Microsoft’s influence on OpenAI’s strategic direction.

The reshaped board comprises Chair Bret Taylor, Larry Summers, and Adam D’Angelo. D’Angelo is the sole member of the previous board. The changes come after a period of intense drama, during which Altman was initially ousted as CEO on November 17. The nonprofit board cited a lack of confidence in Altman’s ability to lead consistently.

However, Microsoft Chairman and CEO Satya Nadella later announced the hiring of Altman and Greg Brockman to support Microsoft’s ambitions in advanced AI. The subsequent developments led to Altman’s reinstatement as OpenAI’s CEO.

The board shakeup also saw the departure of previous members Helen Toner and Tasha McCauley. The inclusion of a non-voting observer seat for Microsoft underscores the deepening collaboration between OpenAI and Microsoft in advancing artificial intelligence initiatives.