Facebook does a lot of work like this for its internal development uses (also, when it used to open source Nuclide).

I think this is a good first step, but there's a lot more problems that are harder to solve than what this offers (and are what I'd consider the main problems that need to be solved...)

One example is language services. Integrating something like C++ autocomplete is difficult, and not something they seem to have done (looking at their page). The right way to do it is to run the C++ autocomplete on the server, and have some way of providing those suggestions over the connection to your local editor.