Converting ArcGIS Online Basemap to new coordinate system for ArcMap?

Question

I have an ArcGIS web application that depends on all coordinate systems of the layers and basemaps to be the same, which I would think is standard practice.

I like to just use the Esri online basemaps such as this one, but it uses 102100 for a coordinate system instead of 4326, which is what I have all my other layers in.

Is there a way I can transform these Esri basemaps into a new coordinate system and publish them to my server via ArcMap?

Am I doing something wrong here and I should be taking a whole different approach, because I would expect other people to run into the same issue as this all the time if they want to use Esri basemaps.

Answer 1

As commented by @Vince:

The Esri basemaps are in the same spherical Mercator projection as Google Maps and Bing Maps. For performance reasons, you generally want to project vectors to the basemap raster (which is the whole benefit of basemaps). You can publish your own basemap, but it's not a trivial effort.