I read the article and was disappointed that the full "word" got cut off, but I know that somewhere, there's a German out there who will post something even longer.

I’m German and think the idea to compound words into one should not really count as the longest / a long word. I mean yes it is but also it isn’t. Like: “ Grundstücksverkehrsgenehmigungszuständigkeitsübertragungsverordnung” In the end it’s just slapping words together and count it as one.