If you get a tax certificate in Dubai, you have effectively︆ paid your taxes in dubai. To get a tax certificate you don't even need to︇ prove anything to the dubai tax authority, they have your biometric data every time you︈ get in and out. And you need either to have a property or a long︉ term rental contract, which is in their system. Once you have that and spend 90︊ days in a year they give you a tax certificate.
If you left your country︋ of origin and have no relationship with it ( I mean, no wife, kids, company,︌ or other type of interest ) the tax certificate from Dubai is all you need︍ to be compliant as long as, as I said, trigger residency somewhere else. And in︎ most european countries triggering residency means either spending more than 183 days in the country️ or having the principal place of interest in the country, which again means kids, wife or business. Although the fact that double taxation agreement exists, makes things even more difficult:
Let's say you own a bar in Ibiza and work there during the summer months, and during the winter months you move to Dubai and work as a software engineer for a Dubai company. How is your money taxed?You are technically tax resident of both countries, and ( but I am guessing here ) you should not pay spanish taxes on money you generated working in Dubai on which you actually already paid taxes, because︀ the money is already generated in Dubai. Things would be different if you did six︁ months in Dubai but kept the restaurant in Ibiza open the whole year, the Dubai︂ tax certificate is worthless.