Marissa Mayer, CEO of Yahoo, taught classes at Stanford before working at Google.
Mayer's leadership skills began to shine during her time at Stanford when she taught a computer science class in symbolic systems. Although she was still an upperclassman at the time, she took to it naturally. Eric Roberts, a computer scientist at Stanford and Mayer's mentor, previously told Business Insider that she was "unusually good at it" and "extremely effective." After graduating with her master's in symbolic systems, Mayer became one of Google's first employees.
Apple's design genius Jony Ive designed a toilet at one of his early jobs before creating luxury gadgets.
Before joining Apple in 1992, Ive worked at a London-based startup called Tangerine. Ive eventually grew tired of his work at Tangerine, but the final straw came when he was assigned to design a toilet for one of the company's clients, Ideal Standard. When Ive presented his final design, it was criticized for being too expensive to build, according to Time.
Sergey Brin, the cofounder of Google, interned at Wolfram Research in the early 1990s.
Before Sergey Brin cofounded one of the most important tech companies in the world, he worked at Wolfram Research. According to an early version of his resume from 1996, he worked as a coder.
Apple CEO Tim Cook delivered newspapers as a teenager, and also worked at a paper mill.
One of the lesser-known nuggets buried in Yukari Iwatani Kane's book "Haunted Empire: Apple After Steve Jobs" is that Tim Cook's first paying job was delivering newspapers in his Alabama hometown. Cook also worked at a paper mill in Alabama and an aluminum plant in Virginia before getting into the tech space, as he said on stage at Goldman Sachs Technology and Internet Conference in 2012. His first job in the technology industry came when he worked at IBM for 12 years just before he started at Apple.
Amazon CEO Jeff Bezos ran a summer camp for kids when he was in high school.
After spending the summer working at McDonald's as a teen, Bezos and his then-girlfriend started a summer camp for kids called the DREAM Institute. They charged $600 per child, but only managed to sign up six students. Even still, it shows that Bezos had the drive to start a business even at a young age. His first job in the professional world after graduating from Princeton with a computer science degree was at an international trade startup called Fitel.
Unsurprisingly, Microsoft founder Bill Gates started out as a programmer.
Bill Gates dropped out of Harvard to start Microsoft, but during his senior year of high school he worked as a computer programmer for TRW.
Facebook COO Sheryl Sandberg helped those with diseases in India during her time at World Bank.
Sandberg's mentor and thesis adviser at Harvard, Larry Summers, hired her to work with him at World Bank in 1991 after graduation, according to CNN Money. She then traveled to India for a project that involved stopping the spread of leprosy in India. After her tenure at World Bank, Sandberg worked as the chief of staff at the White House's Treasury Department during the Clinton Administration.
Jeff Weiner climbed the ranks at Warner Bros. long before he came the CEO of LinkedIn.
In 1994, just two years out of college, Weiner joined Warner Bros. He caught the attention of higher-ups when he wrote a report calling for Warner Bros. to boost its online presence. "I was just a just a little pisher, a nobody," he told Forbes. He eventually became the vice president of Warner Bros.' online presence, as it still says at the bottom of his LinkedIn profile today.
Steve Ballmer, Microsoft's former CEO, helped sell dessert-making machines.
After graduating from Harvard, Steve Ballmer took a job at Proctor & Gamble helping sell a device called the Coldsnap Freezer Dessert Maker. After that, he helped promote the Moist 'n' Easy Snack Cake. Although his early assignments at Proctor & Gamble didn't reflect the path he ultimately took with his career, it shows that he's a versatile salesman. In 2007, he was still able to recite the Coldsnap Freezer Dessert Maker's slogan on stage at AllThingsD's D11 conference: "Makes revolutionary desserts you never could have thought of before."
Eric Schmidt, Google's executive chairman, worked at a company that made chips for the Nintendo Game Boy and Sega Genesis.
After interning at Bell Labs, one of Eric Schmidt's first full-time jobs was working for Zilog, a company that makes chips. In fact, some of Zilog's older chips are found in gaming consoles like the Nintendo Game Boy and Sega Genesis. Schmidt's background also includes holding high-ranking positions at Sun Microsystems and Xerox.
Now check out what some of today's biggest names in tech looked like as kids ...