Fidji Simo, OpenAI's product and business chief and one of CEO Sam Altman's most prominent lieutenants, announced Thursday that she is stepping down from her full-time role at the company to focus on her health, following a "severe exacerbation" of a chronic illness she has lived with for seven years.
The Announcement
Simo shared the news in a lengthy, personal post on X, revealing that she went on medical leave three months ago after her condition worsened significantly. "During that time, it became clear that the road to recovery would be much longer and more complex than I had anticipated—and that I needed to focus on it fully," she wrote. She will remain connected to the company as a part-time advisor rather than departing entirely. Axios and multiple outlets confirmed the condition driving her decision is Postural Orthostatic Tachycardia Syndrome (POTS), a neuroimmune condition she was diagnosed with in 2019, though Simo herself did not name the illness explicitly in her public post.
She was candid about the internal struggle behind the timing of the decision. "When I went on leave, many people told me I was courageous for prioritizing my health," Simo wrote. "The truth is that I am only making this decision now because I failed to make it many times before." She described years of being encouraged by doctors, friends, colleagues, and loved ones to slow down—including an offer from Meta for a full year of medical leave two years after she first got sick, which she turned down without hesitation. "Mark [Zuckerberg] told me I should play the long game," she wrote. "I wish I had listened."
A Career Defined by High-Stakes Roles
Simo's departure marks the exit of one of OpenAI's highest-profile executives. She joined the ChatGPT maker in May 2025 as CEO of Applications, stepping into a role she described as feeling "like a role that my entire career had been building toward." Before OpenAI, Simo led Instacart as CEO, guiding the grocery delivery company to profitability and steering it through an IPO that helped break the longest tech IPO drought in three decades. Prior to Instacart, she spent more than a decade in leadership roles at Meta, including serving as head of Facebook from 2019 to 2021, where she championed the platform's pivot to video.
Reflecting on the throughline of her career, Simo wrote that the same drive that fueled her rise from a fishing family in the Mediterranean port town of Sète, France, to the top ranks of Silicon Valley also made this decision especially difficult. "I grew up believing that opportunities were precious and that when they appeared, you grabbed them with both hands," she said. "But what I'm learning now is that grit and endurance are not the only skills required to have impact over decades. Sometimes the harder thing is to stop, listen, and trust that taking care of yourself today makes it possible to contribute for much longer tomorrow."
A Broader Mission Around AI and Health
Simo tied her personal experience directly to her vision for where AI can create the most value going forward. "It has been a jarring experience to spend my days helping build the future while simultaneously navigating a disabling disease that still has no cure," she wrote, adding that she's spent countless hours over the years "dealing with symptoms, treatments, insurance, uncertainty, and all the invisible work that comes with being a patient." She said the experience has strengthened her belief that "some of the most important opportunities for AI lie in helping people solve real problems in their daily lives: their health, their finances, their time and the everyday burdens that shape human experience" — and expressed hope that AI could eventually contribute to a cure for conditions like hers.
Leadership Transition and Reaction
OpenAI President Greg Brockman had already assumed responsibility for product duties during Simo's medical leave since April, and is expected to continue in that capacity following her formal step-back. Simo thanked Altman, Brockman, and OpenAI's board "for their support during this time and for offering a way for me to continue contributing to the mission without sacrificing my chances of recovery." Altman responded publicly on X, writing that he is "really sad about this and very grateful for all Fidji has done for OpenAI, and even grateful for her friendship and who she is as a person," adding that the team wishes her a speedy recovery.
Context: A Turbulent Stretch for OpenAI Leadership
Simo's exit adds to a string of senior leadership changes at OpenAI, a company that has weathered significant executive turnover in recent years. The news also comes at a pivotal moment for the company more broadly: OpenAI confidentially filed for an IPO last month, a week after rival Anthropic did the same, though OpenAI has not offered a public timeline for a market debut and is reportedly pushing those plans to at least next year.