A bunch of people, but Malte Ubl is one of the main people and has the best tech talks on why they picked the techniques and hacks they did.
I'd recommend watching that for how it works than asking @amphtml questions.
Node people: I did a node specific presentation at LNUG you might like:
I use AMP on CertSimple but appreciate that AMP favors 'speed achieved using specific techniques' rather than speed per se. There's the RealPolitik element where we as site owners have to do what Google say.
Why on god's name anybody would appreciate that?