I am from munich so my opinion may be skewed, but it is at best very average, as in some no name devshop/consultancy would pay this much(and even they tend to pay more).
Nothing I would expext from a Unicorn, but maybe the market in Berlin is THAT different.
In all Western and Northern Europe (except UK and Switzerland), 50K for a junior position sounds about right. It’s around 25K in Southern Europe, and probably less in Eastern Europe.