Today, building a web app usually includes building a web API. In Ruby, you can pick one of common options, Rails or Sinatra, or a new interesting one: Hanami. I'll present in the talk the reasons that pushed me to pick Hanami to develop a web API, a quick tour of the framework and its basics, and how to use it to develop a web API.
code example: https://github.com/toch/takeoffconf2016-jsonapi