During her career as one of the most powerful executives in Silicon Valley, she was put on earth to scale organizations. As an advertising head at Google in the mid-2000s, and as COO at Facebook for 14 years, she oversaw a time when the internet services ballooned to colossal sizes, fed by a seemingly endless fountain of advertising revenue.

Her most significant and complicated legacy may be the tech industry, though she gets most of her name recognition fromLean In.

It became an essential part of every advertiser's budget because of the work done by Sandberg, who was one of the people who made the ad business so enormous. After joining Facebook in 2008, she brought the same self-service model to the social networking company, now called Meta Platforms Inc. Business models that offered products for free and made money off of users' personal data followed an entire industry of other tech companies.

Sheryl had a front-row seat at the two largest and most successful advertising platforms in history. Colin Sebastian, an analyst at Robert W. Baird & Co., wrote that the success of the advertising model is the lasting impact of Sandberg.

Read about her interview and her resignation.

In recent years, her public image was damaged by the mounting criticisms against Facebook, where she was seen as a powerful No. 2 executive. Her expertise in legal, operations and policy made her an asset to the company. Over time, the social network was criticized for its failure to rein in large-scale misinformation, hate speech, and privacy.

Lawmakers frequently grilled the two of them on topics such as foreign interference in elections and losing track of users. The scandals never seem to stop: fomenting ethnic violence in the countries of Sri Lanka andMyanmar, allowing violent video and misinformation to go viral, and abetting the organization of a right-wing insurrection at the US Capitol in 2021.

People familiar with her leadership say that she was critiqued by her employees for surrounding herself with trusted lieutenants who were more interested in keeping bad news to themselves and not addressing problems until they became public crises. According to the Wall Street Journal, she used her power at Facebook several years ago to suppress news about her boyfriend, but Meta says that's not the reason for her departure.

It has been proven that the way Facebook scaled recklessly, intentionally, to dominate the entire, is the most scrutinized part of her legacy, by those who say she pursued growth single-mindedly without pausing to consider its repercussions.

That image is not in contrast to the personal brand that Sandberg has as a leading woman in the workplace, someone who balanced raising a family with career ambitions. Her personal schedule was analyzed by news outlets, which included rules like leaving work at 5 pm and eating dinner with her kids every night. Sheryl told me to use the lessons of Lean In when negotiating for a raise or for career growth. The book evolved from a TED talk and turned into a network of in-person groups around the world. Some readers appreciated her candor and her emphasis on taking charge, while others felt that her advice was hollow because of her wealth and other privileges.

She told graduates to bring their whole self to work and be authentic in their professional life. She posted about the importance of mental health on Facebook. When Hillary Clinton ran for president, it was thought that she could be nominated to be Treasury Secretary, as she had been a mentor to Sandberg. After Dave Goldberg died, she wrote a second book about her grief and how adversity can help.

One of the great things about working for her is that she never wasted anyone's time.

Dan Rose, a venture capitalist who worked for Sandberg for over a decade, wrote that he was held to a high standard by his boss.

The company's money-printing business model and public policy team, which she oversaw, became a lightning rod for controversy over perceived censorship, misinformation, and training politicians who later used Facebook to manipulate the public. In building up the company's roster of employees directly managing those issues, Sandberg was "incredibly instrumental" according to a former Facebook public policy director and Republican aide. She was hired at the company along with the top Republican and vice president of global policy.

Harbath acknowledged that the dynamic had changed in the last few years as the company's owner took a more active role. It is a big change, and it is symbolic, but those who could see the leadership dynamic shift suspected that Sandberg might leave eventually.

She won't say much about what she'll do next apart from focusing on her family and philanthropy. Two people who worked closely with her at Facebook said that it became harder for her to work on women's empowerment or other causes without bringing up her main job. The other person said that she would like to distribute her wealth to causes that are important to her and not worry about whether the moves would create a perception of bias at Facebook.

Eisenstat, the former head of Facebook's elections integrity team, said that she believes that Sandberg can be responsible for the economic outcomes of her career, as well as her legacy. It does not change anything.