I had this scenario(or at least close to it) on the company that I've worked before. We had a nodejs/angular frontend and all the backend were spread across multiple api(each api was a microservice).
It does scale very well, considering that all the microservices are written in ruby.
And for the SEO thing, there was a varnish server before the frontend server that sends bots request to a custom prerender server ( https://github.com/prerender/prerender ).
So basically, normal users were redirected to the nodejs app, and google and others crawlers were redirected to prerender.
I dunno exactly if this is what you want to get with "also provides a server-side render", but I guess it's close to what you're looking for :)
It does scale very well, considering that all the microservices are written in ruby.
And for the SEO thing, there was a varnish server before the frontend server that sends bots request to a custom prerender server ( https://github.com/prerender/prerender ).
So basically, normal users were redirected to the nodejs app, and google and others crawlers were redirected to prerender.
I dunno exactly if this is what you want to get with "also provides a server-side render", but I guess it's close to what you're looking for :)