At this point, we would probably be better off just bolting some lightweight git solution onto our devops tools (which are 100% custom in-house developed), rather than fighting with some more-durably-hosted offering of GitHub, et. al.
Anyone who posts that "but you cant make it more reliable than microsoft" line is not thinking about the dependencies between systems and the considerable impact incurred on a service just by virtue of it being a publicly-accessible platform without any cost barrier to entry. Sure, bringing it in house might bring additional difficulties, but I think I can eliminate a shitload of existing difficulties if we moved from webhooks across the public internet to a direct method invocation within the same binary image.