The road to the corner office does not always begin with an Ivy League degree or a prestigious internship. For Jake Leach, chief executive of medical-device maker Dexcom, it started with a $10-an-hour job washing laboratory equipment.

In the 1990s, Leach was a teenager in California trying to save enough money to pay his way through community college. His high school sweetheart had just finished a summer internship at MiniMed, an insulin pump company, and before returning to school she offered him the chance to take over her job. Cleaning lab equipment such as beakers and flasks was hardly glamorous work, but it would mark the start of a career focused on diabetes management.

Nearly three decades later, Leach runs Dexcom, a company worth roughly $30 billion that develops non-invasive glucose-monitoring systems—technology commonly known as continuous glucose monitoring, or CGM. He never had grand plans to become a healthcare executive, he told Fortune, and says 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."

Early lessons in earning

Leach grew up in California's San Fernando Valley, where his father worked in groundskeeping at a Catholic school and his mother later became 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 badly wanted a $350 bike—an expensive purchase for his family at the time. After learning 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 a lesson 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 capable of tackling everything from plumbing to electrical work, his grandfather often brought Leach along on projects around the house. By the age of 10, Leach was learning how light switches worked, how to wire them, and how electrical panels operated. Those afternoons sparked an interest in electrical systems that later extended to experimenting with old VCRs and building homemade rockets.

His grandfather would also give Leach's eventual career in diabetes technology a personal connection. After the older man's gallbladder abruptly ruptured, the family learned the medical emergency was related to his diabetes, and he went on to take insulin for the rest of his life. Leach did not yet know it, but those experiences would help shape both his engineering interests and his future career.

Leach eventually took classes at Glendale Community College before transferring to UCLA, where he studied electrical and biomedical engineering and became the first person in his family to earn a four-year college degree.

The $10-an-hour job washing beakers and flasks at MiniMed eventually turned into a full-time position. Leach spent seven years at the company, which was acquired by Medtronic in 2001. In 2004, he received an offer to join a startup of 30 people called Dexcom, which was looking to challenge the established diabetes technology industry—a sector that, following the Medtronic acquisition, now included his former employer. The opportunity offered something different: a chance to help build a company from the ground up—and to double his salary from $45,000 to $95,000.

A CEO who never asked for a promotion

More than two decades after joining Dexcom, the 48-year-old Leach has watched the company grow into a healthcare giant. Dexcom went public in 2005, and by 2025 it generated $4.6 billion in annual revenue, served approximately 3.5 million users globally, and employed around 11,000 full-time workers worldwide.

The company has benefited from a shifting diabetes-treatment landscape, including the growing popularity of GLP-1 drugs, which are used to treat type 2 diabetes and have helped bring greater attention to glucose monitoring. Glucose monitoring itself has been transformed during Dexcom's rise: continuous glucose monitors track blood sugar throughout the day, an alternative to the manual fingerstick tests that long defined diabetes care. How monitoring technology and GLP-1 drug treatments continue to intersect is one of the dynamics shaping the market Dexcom competes in.

In January, Leach reached the top of the organization as president and CEO, taking charge of a company that numbered just 30 employees when he walked through the door in 2004. His compensation now includes an annual base salary of $1.15 million—a far cry from the $10 an hour he earned when he first entered the industry.

His ascent was not driven by an elaborate career plan. Leach, who became Dexcom's chief technology officer in 2018 and chief operating officer in 2022, said he rarely thought about what position he wanted next. "It's always been: keep doing a really good job, keep solving big problems, keep fostering leaders, teaching people, [and] learning from other people," he said.

Throughout his 22-year career at Dexcom, Leach said he never once asked for a promotion. Instead, he focused on proving himself in the roles he already held and letting his work speak for itself. He also made a habit of volunteering for the less glamorous assignments his colleagues were not particularly eager to take on.

"A lot of times we tend to focus on our own work and what we're trying to get done, and it's really helpful sometimes to take a step back and say what's right for the company, not necessarily what's right for me or what's right for the function I'm leading," Leach said.

For young workers hoping to distinguish themselves early in their careers, that willingness to look beyond their immediate responsibilities can be a major advantage, he added.

"It's like getting outside your swim lane," Leach said. "Everyone kind of has their functional swim lane. You got to get out of that, and I think that's when you become a more valuable leader for an organization."

This story was originally featured on Fortune.com.