A job abroad, and the taxes forgotten

I spent three years abroad on a Swiss secondment contract. I'm very grateful for the experience.

Now the tax bill is coming my way, and it's bigger than I would have liked.

Today, before taking a step like that, I'd sit down with my tax adviser and go through it calmly: whether I deregister in Germany or not, and what that means for my taxes. Knowing beforehand how I could optimise it would have been great.