title: How to configure Sinatra classic to use Puma
body: <p>I have an old project with classic Sinatra (not modular &lt; Sinatra::Base). How can I make it use the Puma web server instead of Thin? </p>
  
  <p>The only examples on the internet I could find using Puma were with modular Sinatra.</p>
  
  <p>reference: <a href="http://www.sinatrarb.com/intro.html#Modular%20vs.%20Classic%20Style" rel="nofollow">http://www.sinatrarb.com/intro.html#Modular%20vs.%20Classic%20Style</a></p>