I loved that book! But it is unfortunately not a book for everyone, since it has ~1000 pages. It contains both one of the best architecture discussions (IMHO) and a ton of C++ specific advice/rules. So for someone that doesn't have a large C++ code bad, Ousterhouts book is the better suggestion.

How specific is this book to C++? Would you still recommend it to someone who doesn’t work with C++?

It contains lots of c++ specific advice but also general good architecture advice. I would recommend it if you have already read Ousterhouts 'A philosophy of Software design' and maybe one more book and are still curious about the topic. Also there is something of a summary, by himself here: https://youtu.be/d3zMfMC8l5U