This doesn't look good for Python: "Whenever possible, we use Python" "When necessary, we use C++" "As of right now, it ends up that about 75% of our code is C++ and 17% is Python (link) since it turns out that a lot of BIND 10 is performance-critical."
Why doesn't it look good for python? As far as I'm aware, Python has never been advertised as a top-performance language, and part of the advantage has always been that you can rewrite performance-critical paths in c. Adding to this, the fact that BIND is something pretty performance-intensive, I don't think this makes it look bad at all.
This also clashes with the belief in the Python community that performance is not an issue because you just rewrite those few critical sections in C/C++. How's 75% as one possible definition of "few"?