At age 25, Sandberg had graduated at the top of the economics department from Harvard, worked at the World Bank under her former professor, mentor, and future Treasury Secretary Larry Summers, and had gone back to Harvard to get her MBA, which she received in 1995. 

She went on to work at McKinsey, and at age 29 was Summers' Chief of Staff when he became Bill Clinton's Treasury Secretary. 

Her time at HBS was a ways before Google, but that experience helped her see the potential of the internet, she said in a commencement speech to HBS grads in 2012: 

"It wasn't really that long ago when I was sitting where you are, but the world has changed an awful lot. My section, section B, tried to have HBS's first online class. We had to use an AOL chat room and dial up service (your parents can explain). We had to pass out a list of screen names, because it was unthinkable to put your real name on the internet. And it never worked. It kept crashing … the world wasn't set up for 90 people to communicate at once online. But for a few brief moments though, we glimpsed the future, a future where technology would power who we are and connect us to our real colleagues, our real family, our real friends."