Final interpretation of and amendments to the German Constitution, the Grundgesetz, is the task of the Bundesverfassungsgericht (Federal Constitutional Court), which is the de facto highest German court, as it can declare both federal and state legislation ineffective, and has the power to overrule decisions of all other federal courts, despite not being a regular court of appeals on itself in the German court system.
What is Germany's constitution called?
the Grundgesetz