Mike McDerment was still hanging out in his parents’ basement at the age of 30. But he was no slacker reluctant to leave the family nest.

Instead, McDerment was a CEO leading a seven-person team in building a web-based invoicing service called FreshBooks. And his team was operating from the basement as part of a plan to keep costs rock-bottom. McDerment’s ultra-frugal approach protected FreshBooks from running out of cash even as it scaled up dramatically. Five years later, the firm has 93 employees and more than 1.6 million users worldwide.