Personally I have implemented it in a few projects in C# on the backend and front-end (desktop) and also front-end web-applications (typescript). There are a few libraries out there for JSON-RPC in C# but the one I ended up using is vs-streamjsonrpc
over web-sockets. JSON is a nice format for transport but a bit inflated. You can also have a look at MsgPack
binary format which works very well with JSON-RPC when serializing and deserializing it. I have not looked at it for other languages.
What language is your project in?