Rails 5, has been a stellar release moving Rails ahead in current Web ecosystem. With new introductions, like ActionCable, Rails API, Rails is embracing the new directions web is moving towards and has emerged as a good backend for Single Page Apps.
This advances coupled with currently popular ReactJS, has hit a sweet spot, for those who want a more manageable way for their complex views. Rails 5 complement it perfectly
Lets take a look at how ActionCable, Rails API, React powered by Redux(flux), helped us build a realtime App, and how it can help you build a modular Single Page App.