The story of Fidji Simo, a woman from a small southern French town who rose to executive positions at Meta, Instacart, and OpenAI before discovering that the illness that had been subtly following her since 2019 had finally demanded her full attention, has an almost cinematic quality. In July 2026, she announced that she was leaving her full-time position as CEO of Applications at OpenAI to take a part-time advisory role. The cause was an illness for which, in her own words, there is currently no treatment.
The illness is known as Postural Orthostatic Tachycardia Syndrome, or POTS. It is a chronic neuroimmune disorder that affects the autonomic nervous system, the part of the body that controls blood pressure, heart rate regulation, and the basic mechanics of getting out of a chair. Those common mechanics can be anything but for those who live with it. Severe exhaustion, palpitations, lightheadedness, nausea, and fainting are among the symptoms, which are frequently brought on by merely shifting from a seated to a standing position. According to most accounts, it is a draining and often misdiagnosed condition, in part because it mimics so many other conditions and in part because those who suffer from it may appear to be in perfect health. For seven years, Simo had been trying to manage it.
The regret she included in her announcement is what makes her departure especially pointed. She talked about falling ill while still working at Facebook, and friends, coworkers, and medical professionals all urged her to slow down. Meta offered her a full year of medical leave two years into her illness. She declined without giving it any thought. She remembered being advised to play the long game by Mark Zuckerberg. It’s difficult not to read that detail and feel the weight of it—a piece of advice she publicly and unequivocally acknowledged that she wishes she had followed.
Nevertheless, she went on to write an outstanding second chapter. She guided Instacart through a challenging time in consumer technology before joining OpenAI in May 2025, just as the company was getting ready for what many anticipate will be a historic IPO. However, she went on medical leave three months before her announcement following what she called a severe flare-up, a worsening of her condition that made it obvious the recovery would be more difficult and time-consuming than she had anticipated. In her absence, Greg Brockman took over as product manager.
She acknowledged that it was difficult to decide to take a complete step back. “I failed to make this decision many times before,” she said. Perhaps more than any other line in her statement, that one speaks to the reality of high achievers dealing with chronic illness in fields that reward perseverance. In Silicon Valley, there is a specific kind of pressure to perform through hardship, to view slowness as a weakness and endurance as a virtue. Simo appears to have deeply internalized that pressure, and she is now stating that it cost her with some sincere public candor.
She’s not completely leaving. She has established herself at the nexus of technology and chronic illness, which she obviously cares about, through the Metrodara Foundation and ChronicleBio, which she co-founded and uses artificial intelligence to study POTS, ME/CFS, Long COVID, and related conditions. It remains to be seen if that work picks up speed now that she has more time to dedicate to it. However, Simo seems to be redirecting rather than just taking a step back, which is quite different.
Her story serves as a helpful, if unsettling, reminder for the larger tech community. No matter one’s title, aspirations, or financial status, chronic illness does not discriminate. Regardless of IPO timelines or product roadmaps, it usually emerges on its own. And sometimes the decision that takes the longest to reach is the most important one a leader can make.