OpenAI announced this month that it had recruited Simo to lead its applications team, reporting directly to CEO Sam Altman. At the time, Altman said in a post that Simo would "focus on enabling our 'traditional' company functions to scale as we enter a next phase of growth."
She joined the artificial intelligence startup's board last year.
Simo helped take the grocery delivery company public in 2023, after it ballooned in popularity as consumers sheltered at home during the depths of the pandemic.
At the time, Instacart was the first major venture-backed tech IPO since the end of 2021. She also made CNBC's 2024 Changemakers list.