EURO migration in Croatia included replacing domestic currency HRK with EUR and also "joining" domestic currency HRK with the main international currency EUR.
Those are wide and deep changes in banking core systems that require also additional infrastructure, design, implementation, testing, simulations of the conversion/migration and finally D-Day live conversion/migration.
When you add requirement for the "big bang" approach and fixed deadline, project becomes even more complex and demanding especially in final activities with multiple client banks for the migration/conversion weekend, Saturday 31.12. and Sunday 1.1.
Intensity of activities maybe best explains information that Banksoft company successfully performed for 5 core banking clients conversions within 24 hours on December 31st. And next day on January 1st Banksoft successfully performed core system activations and pilot live processing for those banks.
This ensured that those banks could all start normaln business on Januarry 2nd, of course with EURO as a new domestic currency in their core banking systems...
Business media also covered this successful Banksoft project: https://www.poslovni.hr/hrvatska/da-dan-d-nismo-odradili-bez-greske-banke-1-sijecnja-ne-bi-mogle-otvoriti-vrata-4373143
