A long time ago, but still a bit of an achievement. As a first-time entrepreneur, I was contracted by Critex AB, a supplier of electrical equipment, to develop a full scaled ERP system including ledger functionality, salaries, orders, inventory and more. Singlehandedly I drew from my experience with 3L System AB where I was part of developing a similar system for another niche.
The system was completed in about a year and used by Critex for five or six years. Sadly, what skills I had in developing this system, I lacked in marketing it so it died with Critex. It was, however, a full-grown system suitable for a smaller vendor of fast-moving supplies.