At a previous gig, without getting into specifics, we built a huge internal client-server system. The client was written in Node.js and ran as services on both Windows and Linux on a few thousand machines. The server was written in Node.js and ran as a Linux daemon.

Node.js matched the developers' skill sets and gave us the ability to quickly write a server that could easily handle several thousand concurrent requests from the clients. On the client-side, Node.js gave us cross-platform support for nearly free (as well as being within our skill sets).

Looking back, I do not think the project would have gotten off the ground in any other platform in that specific organizational environment. The server on Linux was particularly well-suited as it was architected to scale horizontally but still had room to scale vertically.

On the client side, while we were able to get the Node.js service out pretty quickly, it eventually had performance and integration issues, particularly on Windows. It was super frustrating having to shell out to external processes or write native C++ modules to get access to some needed Windows APIs. In hindsight, I would have tried to rewrite the Windows client sooner in C++ or C#. On the plus side, it was a huge advantage that the entire Node runtime fit in a single executable (no dependencies on a huge JRE or other runtime).

Overall, I would recommend it as an option to consider if most of the following is true:

* Need to get to market quickly * Application is I/O intensive rather than CPU intensive * Dev team already knows JavaScript * Target environment is not Windows

Personally, I decided to move away from Node.js and these days if I was faced with the same problem I would lean toward a JVM language or Elixir.