The solution that synchronous systems use is either creating more processes or threads. But the problem is you either end up wasting resources (as is the case w

The solution that synchronous systems use is either creating more processes or threads. But the problem is you either end up wasting resources (as is the case with one process per request), or have to figure out how to share those resources concurrently without shooting yourself in the foot (and thread-safe programming isn't always easy).