I used to work as a software engineer for Google, working on Android (2005-2014). I spent five years working on Dalvik (2006-2011), and two on system-level graphics (2012-2014).
I've written a few documents for Android developers that now appear on the official site:
Q&A for professional and enthusiast programmers
Q&A for professional and independent game developers
Q&A for enthusiasts and power users of the Android operating system
Q&A for professional programmers interested in conceptual questions about software development
Q&A for passionate videogamers on all platforms
Q&A for meta-discussion of the Stack Exchange family of Q&A websites