That's a very interesting experiment in many levels. Haven't taken the time to look at the paper yet, but I'm curious of how you got your number of pps vs Gb/s in the README :

"full bidirectional load at 20 Gbit/s with 64 byte packets (29.76 Mpps)". sounds like 20Gb/s should be closer to 40Mpps than to 30Mpps. Did you hit CPU limits on the packet generator, or am I missing some packet header overhead ?

Did you try bigger that 64-byte packets ? I'm curious how various runtimes would handle that.

And how long did you run the benchmarks ? I couldn't really figure it out from the github or the paper. Mostly wondering if java and other Gc'd language showed improvement or degradation over time. I could see the JITs kicking in, but I could also see the GCs causing latency spikes.