For deepstream.io we've gotten quite far with a mix of node and c++ with both languages operating on the same buffer of typed arrays.

Our argument for this weird symbiosis was that we wanted the popularity of the NodeJS ecosystem at the time with the performance of C++ - and we achieved this to an at least satisfactory degree.

When it came to building binaries based on the mixed codebases, especially for windows, things were a lot more challenging.