Ten years into his career, William Hagstrom, CEO of Crescendo Bioscience, says he had an epiphany. Working at a billion-dollar company, he remembers leaving a lateral meeting when a colleague approached him and told him to "relax, it's only a job, it's not a crusade." And this comment hit him like a ton of bricks: if he was going to invest his life and time into a venture, it better be a crusade.

Crescendo Bioscience CEO William Hagstrom explains some of the biggest lessons he learned from the early stages of his career. Taking initiative, doing fieldwork, and being objective rank as some of the most useful things he learned while working for large, multinational healthcare firms like Baxter International. What was the most important lesson? Tenacity and relentlessness make all the difference in whether a project succeeds or fails.

How do I think of myself as an entrepreneur?" asks William Hagstrom, CEO of Crescendo Bioscience. As someone who has studied Myers-Briggs personality types, he describes himself as INTP and as someone who is fairly intense and analytical. He also tests high in vision, deliberation and innovation. "It's important to know yourself," he says, "you can't force a style that doesn't work for you." With all this being said, Hagstrom adds, "it's not just about your strengths but also about your passion."

William Hagstrom, CEO of Crescendo Bioscience, remembers an idea from a column in Inc. magazine: "There comes a time when you realize the business needs something you can't give it; at the same time, you realize you need something the business can't give you," A CEO needs to know there are very distinct life cycles in a company's evolution, and business leaders must constantly assess their role and place in these maturation stages as well as their own needs as entrepreneurs.

A few companies into his entrepreneurial life, William Hagstrom, CEO of Crescendo Bioscience, has some advice for those who are just starting out. An entrepreneur must think about and understand risk better, so he can ultimately minimize it. He boils the many insights into some hard-learned lessons: architect the business more deeply and muscle it with talent, so the programs are stouter and the company makes a bigger impact. And while it may seem obvious, he says that a CEO must build in time to think and reflect about what's going on in the business.

From his first experiences as an entrepreneur, William Hagstrom, CEO of Crescendo Bioscience, relates the importance of strategy and its integration into the business model. Added to this vision, he believes a CEO of a healthcare firm must have a thorough knowledge and understanding of the technical and scientific aspects pertaining to the business. Because there is little margin for error, the company leader must also be a multitasking dynamo with sound judgment who can deliver results. In short, the CEO must do more than talk, he must act.