In 2009, Jim co-founded Square, where he now serves as a Director. Jim is also a General Partner at FINTOP Capital and Green Visor Capital. He serves as a Director of the St. Louis Federal Reserve and as a Trustee to Washington University in St. Louis.

Jim's first venture was co-founding Mira Digital Publishing in 1990, which is a leader in electronic publishing for scientific conferences. In 2013, he founded the LaunchCode Foundation, currently bringing free computer education and jobs to 5 US cities.

In addition to his businesses and philanthropy, Jim is a glassblowing artist and co-founded one of the nation's top glass centers, Third Degree Glass Factory. He has published two books on computer programming and one on glassblowing. He is a graduate of Washington University in St. Louis.