Xavier de Gaye is a Python core developer since June 3, 2016. I just noticed that his grant wasn't logged in the devguide: it's now fixed (online doc not up to date yet): https://docs.python.org/devguide/developers.html#permissions-history
Xavier already pushed some changes to enhance Android support in CPython 3.6. I helped him to learn the CPython workflow (Mercurial, bug tracker, etc.).
I consider that he knows understand well the process and I don't need to mentor him. But I will probably continue to help him to review his patches, answer to questions, etc.
It looks like the Android port is also related to cross-compilation, so it looks like CPython 3.6 will be easier to cross-compile as well. Great!
For Android, the HQ is the "Meta-issue: support of the android platform" https://bugs.python.org/issue26865