CNN Business  — 

For much of her first decade at Facebook, Sheryl Sandberg’s public stature grew alongside the size and influence of the company she helped run. As second-in-command to Facebook cofounder Mark Zuckerberg, she oversaw the massive growth of its core advertising business while positioning herself as an icon of corporate feminism.

When she joined Facebook as COO in 2008, she was the rare woman in the C-Suite of a tech company. Her book, “Lean In,” was released five years later, and it launched a movement of the same name to inspire a generation of women to speak up in the workplace and beyond. By 2016, Sandberg was viewed as a possible CEO candidate for Disney and was also said to be in consideration to serve as Treasury Secretary under Hillary Clinton.

But as Facebook’s reputation shifted after the 2016 presidential election, so did Sandberg’s. Facebook faced criticism for enabling the spread of misinformation and conspiracy theories that posed a threat to democratic institutions. It was hit by the massive Cambridge Analytica privacy scandal in 2018. And more recently, the company, now called Meta, came under fire from whistleblowers and lawmakers for allegedly putting profits over people, and ignoring its platforms’ apparent harms for young users. During that time, Sandberg and Zuckerberg were each called to testify before Congress and issued a number of public apologies.

Now, Sandberg is set to step down as COO this fall after a dizzying 14-year-run, with plans to focus on philanthropic efforts while remaining on the company’s board. But as she looks to her next act, she leaves behind a complicated legacy that partly mirrors the legacy of the organization itself.

In the hours after Sandberg announced her planned departure on Wednesday, she was praised by a number of prominent figures in tech and media. Venture capitalist Bill Gurley said Sandberg had “a simply unbelievable run” and noted “the vast majority of the $500B in market cap was built after she joined.” Media mogul Arianna Huffington called her a “champion of women.” And Fidji Simo, Instacart’s CEO and a former Facebook executive, said Sandberg “inspired so many of us to reach for more - and to do so unapologetically.”

Other industry watchers, however, stressed the negative impacts from Facebook that emerged during her watch and pointed the finger at her for not doing more to prevent them.

Mark Zuckerberg walks with Sheryl Sandberg after a session at the Allen & Company Sun Valley Conference on July 08, 2021 in Sun Valley, Idaho.

“Her decisions at Meta made social media platforms less safe for women, people of color, and even threatened the American electoral system,” Shaunna Thomas, the co-founder of UltraViolet, an advocacy group for gender equity, said in a statement. “Sandberg had the power to take action for fourteen years, yet consistently chose not to.”

Shoshana Zuboff, a professor emerita at Harvard Business School and author of several books on how technology is impacting society, told CNN that she believes Sandberg’s work in finding ways to monetize users’ personal data makes her “responsible for the wholesale destruction of privacy.”

Meta, Facebook’s parent company, declined to comment for this story beyond the public posts from Sandberg and Zuckerberg. In her post, Sandberg noted how much social media issues had changed from the time she joined the company.

“The debate around social media has changed beyond recognition since those early days. To say it hasn’t always been easy is an understatement,” she said. “But it should be hard. The products we make have a huge impact, so we have the responsibility to build them in a way that protects privacy and keeps people safe.”

“I and the dedicated people of Meta have felt our responsibilities deeply,” she added. “I know that the extraordinary team at Meta will continue to work tirelessly to rise to these challenges and keep making our company and our community better.”

Facebook COO Sheryl Sandberg is sworn in to testify before the Senate Intelligence Committee on Capitol Hill in Washington, DC, on September 5, 2018.

The adult in the room

Sandberg joined Facebook after holding senior roles at Google and the Treasury Department. She was widely viewed as being the seasoned hand at a company run by a twenty-something founder and exploding in growth.

“She came in in the era where people were like, ‘These founders need adults in some of these companies,’ and she got a ton of attention for it,” former Facebook employee Katie Harbath, who now is CEO of the consulting firm Anchor Change, told CNN Business. Harbath added that, “in some ways, Mark and Sheryl were co-CEOs.”

Sandberg presided over the company as it grew from roughly $150 million in annual revenue to $117.9 billion last year. She also oversaw public policy, legal and human resources as the company’s headcount grew from 500 employees to nearly 78,000. In her role, she became an ambassador for the company and sometimes met with world leaders in place of Zuckerberg.

Under Sandberg’s leadership, Meta employees conducted anti-bias trainings and she is credited for helping institute some of the coveted benefits employees still enjoy — such as support for employees who want to freeze eggs and expanded bereavement leave, following the sudden death of her husband. (Sandberg spoke candidly in public about helping people talk about grief, even at work.) She also is seen as a major force behind Facebook’s decision to create a Civil Rights team.

In recent years, however, Sandberg featured in multiple PR scandals at the company. That includes a New York Times investigation that found Facebook had attempted to ignore and conceal Russian interference on its platform (a claim the company has pushed back on) and that it had hired a public relations firm that dug up dirt on its competitors and allegedly circulated information on billionaire George Soros, which attempted to link him to groups pushing for more regulation of Facebook.

Sandberg appears alongside other tech execs during a meeting with President-elect Donald Trump at Trump Tower, December 14, 2016.

Sandberg’s role publicly representing the company also appeared to shift in later years. To help manage the public policy part of Facebook’s business, the company hired Nick Clegg as head of global affairs in 2018. While the former UK deputy prime minister reported to Sandberg, it also meant relieving Sandberg of a portion of her portfolio and reducing her profile — which, according to a 2021 report by the New York Times, partly highlighted a rift between Sandberg and Zuckerberg that had emerged during the Trump administration and only widened over time. (Facebook disputed the Times’ characterization of their relationship.)

At the same time, Sandberg arguably remained constrained in speaking out publicly on certain issues due to her leadership role at the company. Harbath said Sandberg always had “causes she wanted to work on, but being COO at Meta, there’s always a limit to how outspoken you could be.”

That could change once she leaves.

Sandberg’s next act

In her announcement this week, Sandberg said she is “not entirely sure what the future will bring.” She has plans to get married this summer and wrote that she hopes to focus “more on my foundation and philanthropic work, which is more important to me than ever given how critical this moment is for women.”

Rachel Thomas, co-founder and CEO of Sandberg’s women’s advocacy foundation, told CNN that she is “thrilled” Sandberg will now be able to assist more in the work of the foundation.

“Sheryl brought new energy to the conversation about women’s leadership, and she founded LeanIn.Org to do her part to advance women in the workplace,” Thomas said in an emailed statement. “With more of Sheryl’s insights and energy, we’ll be able to do more, more quickly, and that’s exciting.”

Sandberg's book, "Lean In," helped launch a movement of the same name to inspire women to speak up in the workplace and beyond.

Renewing her focus on women’s advocacy and empowerment work, while not being the public face of a controversial tech giant, could potentially help bolster some of the positive portions of her legacy. But it remains to be seen whether Sandberg will find her way to the CEO role at another large tech or media company as she once seemed destined to do.

In an interview with Bloomberg, Sandberg said it was “pretty unlikely” that she would take another job in business or in politics, but added, “I learned a long time ago: Never make any predictions about the future.”

CNN’s Brian Fung contributed to this report.