Can Unity trigger building a dependent external DLL as needed?

Question

I have a project which uses some custom asset importer code. As stated here "In a production pipeline AssetPostprocessors should always be placed in pre-built dll's in the project instead of in scripts."

So I created a new VS project and built that DLL and it all works fine. However, being part of a production pipeline, I now also have to build that DLL.

For developers just pulling the code, the DLL won't exist. Is there a simple way of setting this DLL as a dependency and having Unity launch VS to build it? Or, do I need write a script with an [InitializeOnLoad] function to detect the absence of this DLL and then (somehow) fire off the build of that DLL in Visual Studio?