I have some back end .net code that I need to access locally from my Win8 metro app.
Would it be better to expose the back end code via WCF services. I am assuming the .nettcp binding will work? or would it be better to create a brokered windows runtime component as described here: https://code.msdn.microsoft.com/windowsapps/Brokered-Windows-Runtime-9d64cada
After investigating this further I found that you can call WCF services with a NetTcpBinding but not a NetNamedPipeBinding. For a list of supported bindings you can refer to this article here: http://blogs.msdn.com/b/piyushjo/archive/2011/10/19/wcf-for-metro-apps-supported-functionality.aspx
I have chosen to go down the Brokered WinRT component path for performance reasons. This is a very good article to help you get started: http://devhawk.net/2014/04/25/brokered-winrt-components-step-one