Hipermarket is ERP application for over 10 years on the market. It is used by biggest Polish trading companies. The original version was written in C utilizing NCURSES. My job was to adapt the whole business logic written in C to the Qt frontend.
It was very challenging project due to many years of developing the original application by hundreds of programmers. It was needed to become acquainted with custom framework developed by the client and develop a common approach to many different styles ingrained for a very long time.