Brad Lightcap, OpenAI's longtime chief operating officer, has announced he is leaving the company to "start something new," according to an internal message he shared publicly on Tuesday. Lightcap is one of OpenAI's longest-serving executives, and his departure adds to a wider reshuffle of senior leadership at the AI lab as it prepares for a significant initial public offering.

Lightcap joined OpenAI in 2018 and previously worked with chief executive Sam Altman at venture capital firm Y Combinator. He served as chief financial officer for four years before becoming COO in 2022, a role he held until earlier this year when he moved to lead special projects amid an executive shake-up. In his farewell note, he praised the teams he helped build across finance, legal, people and partnerships, and hinted at future plans without giving specifics. His exit follows other recent high-profile departures, including AGI development lead Fidji Simo, former Sora head Bill Peebles, and science vice-president Kevin Weil.