Abir Sen gives new meaning to the term “serial entrepreneur.” Since the late 1990s, Sen has co-founded a series of companies that have capitalized on changes in the health care landscape. His past includes Definity Health (sold for $300 million to UnitedHealth Group in 2004), RedBrick Health and Bloom Health. “I have no interest in climbing the corporate ladder,” Sen told Twin Cities Business earlier this year. His latest enterprise? Minneapolis-based Gravie, a broker that helps people shop for individual health plans. The company is off to a healthy start: Since launching in 2013, it has raised $13.1 million in venture capital.