Material design is something that I have not had time to write about yet (but believe when I say that I will!).
Fortunately there's no shortage of others talking about it. Today, Google's Android Developers blog released a great post about the process they used to build the Google IO app for this year's conference.
As the IO app is available as open source it is probably the best example to look at (we can find out how everything is implemented). Take a look at the YouTube video by Roman Nurik as well as the actual article explaining their design decisions.