I do not see anything less feasible doing it with threads / forks.
Asynchronous IO like in Go I think is useful in a sense that if some of the networked responders are temporarily slow then they will not hold fast ones and would not accumulate threads. If however it is disk / database, then by immediately switching to a next method this strategy will let internal async tasks piling up indefinitely and saturating resource pools of OS just as well. So those "concurrency focused" languages are not a silver bullet and one has to understand internal mechanics to properly manage requests lifecycle.
