Deploy static sites to heroku and use heroku caching

config.ru

use Rack::Static, 
  :urls => ['/css', '/images'],  # put directories here, files will get served for free
  :root => "public"

run lambda { |env| 
  [
    200, 
    { 'Content-Type' => 'text/html', 'Cache-Control' => 'public, max-age=86400' }, 
    File.open('public/index.html', File::RDONLY) # Point this at the starting file
  ] 
}