I used to do thread-per-request, that has mediocre scaling at best. Even on the JVM this barely scales to a few thousand connections; native threads are heavier than that.

I've also done a lot of task-per-request (with each thread's affinity locked to a single hardware thread to avoid ripple effects), which does scale at least an order of magnitude more than threads.

I now use fiber-per-request for the best of both worlds: the easy sequential model of threads, yet the simple performance of tasks.

I can't understand why someone would defend the thread-per-request model at this point. It wasn't even a good model 10 year ago.