GraphQL seems to be a good way to go, much better than RESTful API, no issues with API versioning and under/over fetching, great tooling - GraphiQL IDE. As of Relay, there are some alternatives, Apollo is being the most promising one. For small apps it might be a good idea to use GraphQL server directly, unless you're already comfortable using Relay or another GraphQL client. For larger apps, you may want to evaluate Relay, Apollo, Lokka to check what better suites project's needs.

Lee Byron in this recent AMA said that some services inside FB are using GraphQL. So, it seems that GraphQL can certainly be used in projects, but I am not sure about the community support.

May be someone with GraphQL knowledge can help us here. @koistya What do you think? Would love to see your perspective!

Not every project. It have certain advantages. My colleague wrote an article comparing Restful API vs GraphQL. moesif.com/blog/technical/graphql/REST-vs-GraphQL…