[ionrock]

Most services that might be considered "backends" (ie databases, queues, cloud services) end up being in written in languages that can safely use async techniques for I/O and still use real threading or some other method for managing CPU bound problems.

Many of the applications people think of for node.js end up being "glue", much like python, and can live within this constraint for a very long time, where the I/O optimization is a nice benefit.