He went from washing lab equipment for $10 an hour to leading a $30 billion healthcare company. His advice to Gen Z: Raise your hand

The road to the corner office doesn’t always start with an Ivy League degree or prestigious internship. For Jake Leach, it started working as a lab dishwasher for just $10 an hour.

Back in the 1990s, Leach was a teenager trying to save enough money to pay his way through community college in California. His high school sweetheart had just wrapped up a summer internship at MiniMed, an insulin pump company, and before heading back to school, she offered Leach the chance to take over her job.

It wasn’t exactly glamorous work cleaning lab equipment like beakers and flasks, but it would mark the start of an entire career focused in diabetes management . Nearly three decades later, Leach is now the CEO of Dexcom , a roughly $30 billion company that develops non-invasive glucose-monitoring systems.

And while he never had grand plans to be a healthcare executive, he told Fortune that his climb up the career ladder has come down to one simple recipe:

“It’s all about hard work,” Leach said. “There’s no shortcut.”

Leach grew up in California’s San Fernando Valley, where his father worked in groundskeeping at a Catholic school and his mother was later a teacher’s aide. Money was tight, but he learned early that if he wanted something, he would have to find a way to earn it himself.

In elementary school, for example, he desperately wanted a $350 bike—an expensive purchase for his family at the time. When he learned about layaway, he decided he could save up for it himself.

“With the income of my family, I had no business having that kind of a bike, but I just wanted it so bad,” Leach said.

He spent the summer washing cars for $2 apiece, slowly putting money aside until he could afford it. The experience taught him something that would follow him throughout his career.

“Hard work gets you what you want, and you know you may not always succeed, but you can control it—you can control that outcome,” Leach said.

He also developed an early fascination with how things worked, thanks in part to his maternal grandfather. A handyman who could tackle everything from plumbing to electrical work, he often brought Leach along to work on projects around the house. By the time he was 10, Leach was learning how light switches worked, how to wire them, and how electrical panels operated.

Those afternoons helped spark an interest in electrical systems that eventually extended to experimenting with old VCRs and building homemade rockets.