This is what we've done. Start with Rails behind nginx, add varnish caching when needed, redis when needed, node (or golang or w/e) when necessary for the real

This is what we've done. Start with Rails behind nginx, add varnish caching when needed, redis when needed, node (or golang or w/e) when necessary for the real time bits, etc. Get's a bit messy with all these moving parts, but I think that's the just the nature of large projects. Elixir + Phoenix looks interesting though...