I am a member of Facebook's HHVM team, a C++ and D pundit, and a Machine Learning guy. Ask me anything!
My name is Andrei Alexandrescu. I've been a Research Scientist at Facebook for almost four years, during which I've worked on various projects mainly around Machine Learning and systems programming. In January I joined the HHVM project, which aims at improving the productivity and performance of PHP on Facebook's server infrastructure.
I've also written a couple of books: Modern C++ Design, C++ Coding Standards (together with Herb Sutter), and The D Programming Language, as well as some papers and articles. Some of my talks are on video (this is the most recent).
Looking forward to answering your questions!