Bindings seems to be very slow for a simple operation

Yes, this is nodejs and we are calling bindings within event loop of NodeJS if we had networking layer working on the same thread… that would be so much worse.

There are no parallel threads at all, just two of them - Main Thread and Network Thread. There are couldn’t be any concurrent requests and also IRC C bindings must be called from the same thread that created them, so concurrency are not possible.