I am not sure what the backend and runtime are now but it does seem a bit sluggish coming from a person who works on embedded systems.
I love Industrial Edge. It's by far the best in its class. It seems like the most concerning element is resource optimization.
For example on a 2GB VM I couldn't put IIH essentials plus data flow monitor plus S7 connector. It feels like we should be able to run all the core apps pretty efficiently. I know the RPC clients are all Golang but I am curious.
We write all our edge apps in Rust for precisely this reason.
I believe a lot is written in "Go" but i don't have any proof.