yes doesn't do string concatenation, at least not in the loop that matters. It just prepares a buffer of bytes once and writes it to stdout repeatedly.
I usually do a kubernetes cluster on top of VMs. But sometimes when I really want to scale the standard cloud server less platforms all support /dev/null out of the box. (Except for Windows...)
Still need an adapter library though! Fortunately there are about 7 competing implementations on npm and most of them only have 5-6 transitive dependencies.
However with a single server, it doesn't perfectly linearly scale with multiple clients. I'm getting
1 client: 5GB/s
2 clients: 8GB/s
3 client: 8.7GB/s