Windows Azure and Node - Remember to specify the version

I kept finding that my back end code would subtly fail on something once deployed to an Azure site despite working fine in my own environment. Having hit the problem again recently, I again looked through the server logs to try to identify the problem assuming that again Node would be throwing an error over some very simple syntax.

Then I noticed the following:

"The package.json file does not specify node.js engine version constraints"
"The node.js application will run with the default node.js version 0.10.32"

This is old, in fact to put this into perspective the contemporary node change logs start from 0.12.0 which is the beginning of 2015. I had to go through their archive to find out where this version is from, which is October 2014!

Now I know, the solution is to specify the node engine that Windows Azure should use. e.g.

As soon as I had made this change my problems went away as you may expect. Looking at the latest "how to" guide on the Azure website for node development I notice that this features at step 5. However, for those who have legacy node websites on Azure, this is not so intuitive.