Jack worked at Casa Juan Diego (Dorothy Day Catholic Worker House) upon graduation from Harvard Business School and Harvard Law School. Casa Juan Diego served immigrant Central American families at the Mexico-Texas border. He then joined Goldman Sachs where he became a Partner in the Investment Banking Division. In 2000 he retired from Goldman Sachs to teach high school at Hales Franciscan High School in the inner-city of Chicago, where he taught for three years. Jack launched REX in 2014, whose social mission is to build homes and schools for families living in extreme poverty and to help support Blaze Kids Academy in creating homes and access to quality education for children who have lost access to their parents.