Rack level reverse proxy. Route requests to services with pure Ruby if that's your boat. The boat won't be pretty fast, but you can deploy it on your Heroku's, and what-not-fancy-cloud-services, without a bit of complications. The proxy can sit after the request authentication, or before it, depending on the services you have to route requests to. You can rewrite requests URLs, and the whole Net::HTTPRequest to be sent out.