Simo joined the board of Instacart in January of this year; she’ll take over as CEO from the delivery service’s founder, Apoorva Mehta, as the startup approaches a possible initial public offering.

“Leaving behind the privilege of leading the Facebook app is very hard, and I would only do so for the chance to be part of building an epic company again,” Simo wrote in a LinkedIn post.

The exec has been at Facebook for a decade, where she rose from overseeing product marketing for advertising to running the Facebook app. That role included working on products like the news feed, marketplace, groups, stories, and more. She will be replaced by Tom Alison, who served as her No. 2, according to Bloomberg, which also reports that, with her departure, all of Facebook’s highest-ranking product executives will be men.

The announcement of Simo’s exit comes amid some notable changes among the top female executives at the social network. Carolyn Everson, a leading advertising executive, left the social network after a decade last month. (Facebook named Nicola Mendelsohn, head of the EMEA region for Facebook’s Global Business Group, as her interim replacement.) And the morning of Simo’s news, the New York Times published an article describing how chief operating officer Sheryl Sandberg’s influence at the $86 billion business has waned in the past half-decade.

At the time of Facebook’s 2020 diversity report, women held 34.2% of leadership roles at the company.

The company didn’t immediately respond to request for comment about Simo’s departure and the larger role of women leaders at the company.

Before she started at Facebook, Simo worked on the strategy team at eBay in the late 2000s. She recently appeared at Fortune‘s Most Powerful Women Next Gen Summit, where she discussed Facebook’s competition with Apple and her own personal health challenges; she launched Facebook Live while on bedrest.

While much of Simo’s role leading Instacart will focus on logistics and technology, she wrote via LinkedIn that she plans to apply her experience in advertising by working with “[consumer-packaged goods] companies big and small to help them get their products discovered.”

Mehta, who will become chairman for Instacart, added in a statement: “With Fidji, we have the right leader in place who has the experience we need to help make Instacart’s vision a reality.”