The person asking the question maintained three websites under three different country code top level domains (ccTLDs). The ccTLDs were .fr (France), .be (Belgium), and .de (Germany). The project was a migration from one domain name to another domain name, each within their respective ccTLD, like example-1.fr to example-2.fr.
Read MoreTwo out of the three site migrations failed and lost traffic. Only one of them experienced a seamless transition.