Hello, and Welcome to DobermanTalk! I am from Canada
I think you sound like you'd make a fine home for a Dobermann/Doberman (Pinscher) with one or two caveats:
Firstly, while you do plan on moving to the country side in Portugal, until then you will be in Berlin and bringing the dog to places where there will be presumably be other people coming and going. You will have to work very hard to socialise your puppy in your office and studio setting - and by which I mean, teaching your puppy that strangers coming and going out of these places is normal and expected, and to be ignored. Because the breed is naturally watchful, alert and even somewhat suspicious, their natural response to strangers coming and going will be to warn you. However this can be curtailed with adequate training and socialising.
The second caveat. Being in Germany, if you get a dog from a breeder there, there is a good chance that you will end up with a dog who is not only medium to high energy, but also has the mental drive to do something. This doesn't mean you have to compete or work with your dog, but you will have to invest time working your dog's brain, and not simply expending their energy by playing and running. They are highly intelligent, thinking dogs and they need to either have a job or think they have a job. Puzzle toys, teaching them tricks, challenging their self-control are all things that qualify, and you will have to account for time spent working your pup's brain on top of exercising their body
If you know you are capable of investing the time, patience and consistency in doing these things I think you'd be a perfect fit. I know Germany has pretty strict laws about keeping dogs as well though so I am sure you're already at least half prepared for the considerations needed.