A lot. I know of a few people using my library are in finance doing some crypto currency stuff and the feeds are JSON and/or done via JSON-RPC I think. I didn

A lot. I know of a few people using my library are in finance doing some crypto currency stuff and the feeds are JSON and/or done via JSON-RPC I think. I didn't really get into the details. But even then, doing 2ish GB/s isn't that bad. But people seem to think of C++ as only systems language only ignoring the decades of desktop usage and existing software. Plus web services running are using small fractions of the resources that systems like node use. I know in some examples I have done where a C++ web service used about 3MB of ram, plus usage depending on size of the request, whereas Node started at 300MB. With cloud costs, that's a lot more bang for buck. But JSON is the lingua franca of networked I/O these days, need to interop