I think the improvements to turbolinks in Rails 5 make pjax more of an option now. Also, for scaling remember it's not the end of the road for Rails when you're

I think the improvements to turbolinks in Rails 5 make pjax more of an option now. Also, for scaling remember it's not the end of the road for Rails when you're running out of processes to keep up with requests. JRuby 9000 has been gathering a lot of momentum recently and promises huge performance gains when Truffle and Graal kick in. Migrating a Rails app to JRuby is not that difficult.