The medical records of 8 out of 10 Americans sit on a farm in Wisconsin. Epic Systems did $6.7 billion in revenue last year. Judy Faulkner started it in 1979 with $70,000, writing the original code herself in a basement apartment. She has never raised a dollar of venture capital and has never acquired another company. Every line of software gets built in-house. The campus covers 1,670 acres. About 750 of them are working farmland with sheep, cows, and one donkey. Buried 74 feet under a…