American Marconi Wireless News - OpenAI number two Simo steps down to focus on health

Simo, who joined the ChatGPT-maker in mid-2025 as CEO of Applications and became one of chief executive Sam Altman's top lieutenants, said in a post on X that three months of medical leave had made clear her recovery would take far longer and be more complex than expected.

"I am only making this decision now because I failed to make it many times before," she wrote, revealing that over seven years of illness, she had repeatedly ignored advice to slow down.

The 40-year-old French-American executive had been on medical leave since April due to a severe flare-up of postural orthostatic tachycardia syndrome (POTS), a neuroimmune condition she has lived with since 2019.

Her departure is the latest in a string of senior leadership changes at OpenAI, which has weathered significant executive turnover in recent years and has filed for a high-stakes IPO.

Simo said that what propelled her career -- from a fishing family in the Mediterranean port of Sete to the top ranks of Silicon Valley -- also made stepping back extraordinarily difficult.

"I grew up believing that opportunities were precious and that when they appeared, you grabbed them with both hands," she wrote.

"OpenAI in particular felt like a role that my entire career had been building toward."

Prior to her leadership role at OpenAI, Simo steered grocery delivery platform Instacart to profitability after joining as CEO in 2021. Before that she spent a decade at Meta, where she championed the company's pivot to video.

Despite leaving her full-time position, Simo signaled she remains deeply invested in AI's potential to transform healthcare. She said she would continue contributing to OpenAI as an advisor.

"I am 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," Altman wrote on X.

"We all wish her the best for a speedy recovery. This sucks."

H.E.Young--AMWN