Angular 1.5, Tornado 4.2 & RethinkDB 2.3.5 for me. Tornado coroutines play beautifully with Rethink queries and change feeds. I've also got a proprietary C++ framework in the middle tier, so some of the server processes are C++ Python hybrids. Fortunately Tornado makes it easy to dispatch events into the C++ code via a think wrapper built in Python's C++.