Exactly 15 years ago this month, I spoke with Sean Fitzgerald, a physics and chemistry graduate who had given up a career in microelectronics to launch his own business. At the time, Sentenial employed 14 people, one of whom was an old college friend who had set up the interview. An electronic payments company based in Co Kildare, Sentenial had just raised €1 million through debt finance and funding from Enterprise Ireland. However, Fitzgerald was quick to point out that neither backer was taking an equity holding in the business and that the money would be paid back. “We did…