Here's a story for you: I was born and raised in Switzerland, but I live in Germany now. When I first moved here, I was working as a freelancer and needed to register as a sole entrepreneur (Einzelunternehmen, one of the legal entity forms here).
Now, there are several types of taxes you pay in Germany based on your income. One of them is the income tax, the other is called Gewerbesteuer (maybe best translated as "commmercial tax) - and the Gewerbesteuer can be significant (something like 12% of your income). Many freelancers are exempt from the Gewerbesteuer, and so are software engineers. However, I learned that you only qualify as a software engineer if you have actually studied software engineering or a closely related field. I had studied business administration. I tried to explain to them that I have been working as a software developer for over 10 years, literally doing the same job as somebody who had studied software engineering - to no avail. They woulnd't exempt me from the Gewerbesteuer.
I'm not claiming that I'm an "engineer" or that my computer science fundamentals are as good as somebody who studied computer science, but the tax exemption shouldn't be on some bureaucratic difference like what you studied a decade ago, rather on what kind of job you're doing.
Welcome to Germany!