OpenAI is losing one of its most senior leaders after Fidji Simo, the company's second-highest ranking executive, announced she is stepping down from her full-time role following an extended medical leave.
According to reporting by The Wall Street Journal, Simo informed employees in a staff note on 9 July that her recovery had taken longer than anticipated. She will now transition to a part-time advisory role, ending her day-to-day operational responsibilities at the company.
The move creates a significant leadership gap for OpenAI, which is expanding rapidly while reportedly exploring a future public listing.
A shortened tenure in a pivotal role
Simo joined OpenAI's board of directors in 2024 before taking on a newly created executive position in May 2025 as CEO of Applications.
Reporting directly to CEO Sam Altman, she was tasked with bringing together the company's product and commercial operations under one leader.
Her appointment also reshaped OpenAI's leadership structure.
Several senior executives began reporting to her, including:
- Brad Lightcap, Chief Operating Officer
- Sarah Friar, Chief Financial Officer
- Kevin Weil, Chief Product Officer
The restructuring enabled Altman to devote greater attention to research, compute infrastructure and AI safety.
Medical leave becomes a permanent transition
Simo first disclosed her health challenges in April after revealing she had experienced a relapse of a neuroimmune condition and would take medical leave.
In her latest staff communication, she said the leave had proved "longer and harder than expected", leading to her decision to step away from a full-time executive role while continuing to advise the company.
Her announcement follows several leadership changes across OpenAI in recent months. The same April memo also confirmed:
- Brad Lightcap would move into a new special projects role.
- Chief Marketing Officer Kate Rouch would leave the company to focus on cancer recovery.
- Kevin Weil has since departed the organisation.
From Meta and Instacart to OpenAI
Before joining OpenAI, Simo built her reputation in consumer technology.
She served as Chief Executive Officer of Instacart from 2021, leading the grocery delivery platform through its 2023 initial public offering.
Earlier in her career, she spent more than a decade at Meta, where she held several senior leadership roles, including overseeing the Facebook app.
At OpenAI, her focus centred on expanding the company's consumer business as ChatGPT became one of the world's fastest-growing AI products.
According to TechCrunch, slowing ChatGPT growth late last year prompted the company to place greater emphasis on AI coding tools, where competition from Anthropic has intensified.
Leadership questions emerge ahead of possible IPO
Simo's departure comes at a sensitive time for OpenAI.
According to The Wall Street Journal, she had been widely viewed as a potential candidate to assume broader operational responsibilities if the company proceeded with a public listing.
Her exit now leaves Altman looking for a successor while OpenAI continues scaling its commercial operations. The company's executive leadership currently includes:
- Sam Altman, Chief Executive Officer
- Brad Lightcap, Chief Operating Officer
- Sarah Friar, Chief Financial Officer
- Greg Brockman, President and Co-founder
- Denise Dresser, Chief Revenue Officer
TechCrunch noted Dresser, who previously served as CEO of Slack and spent 14 years at Salesforce, could potentially take on expanded responsibilities, although OpenAI has not announced any leadership changes.
Altman pays tribute
Shortly after reports of her decision emerged, Simo confirmed the news publicly on X.
Altman responded with a personal message expressing both gratitude and sadness.
He wrote that he was "really sad" about her departure, thanked Simo for everything she had contributed to OpenAI, praised her friendship, and wished her a speedy recovery.
Departure coincides with major product launch
Simo's announcement arrived on one of OpenAI's busiest product days this year.
The company unveiled its new GPT-5.6 model family, introducing Sol, Terra and Luna, alongside ChatGPT Work, an AI agent designed to complete multi-step workplace tasks such as drafting documents, spreadsheets and presentations.
OpenAI positioned both launches as part of its competitive push in enterprise AI.
Equity strategy reflects talent competition
Simo also played a role in reshaping OpenAI's employee equity approach during one of the industry's most competitive hiring periods.
According to TechCrunch, OpenAI:
- Reduced its employee equity vesting cliff from 12 months to six months in April last year.
- Eliminated the vesting cliff entirely for new hires in December, allowing equity to begin vesting from day one.
- Was projected to spend $6 billion on stock-based compensation during 2025.
The changes were introduced as AI companies competed aggressively for specialist talent.
There is no indication Simo's departure is related to compensation. Executive equity packages are negotiated separately from standard employee plans.