Apollo Federation Sample
https://github.com/quick-xp/apollo-federation-sample/tree/master/account-ruby-2.4/README.md
https://github.com/quick-xp/apollo-federation-sample/tree/master/product-ruby-2.4/README.md
https://github.com/quick-xp/apollo-federation-sample/blob/master/review-ruby-2.4/README.md
https://github.com/quick-xp/apollo-federation-sample/blob/master/gateway/README.md