Ask HN: When should I use GraphQL

    type Error {
      message: String!
    }
    
    type Query {
      hello(name: String!): QueryHelloResult
    }
    
    union QueryHelloResult = Error | QueryHelloSuccess
    
    type QueryHelloSuccess {
      data: String!
    }

    query {
      hello(name: "World") {
        __typename
        ... on Error {
          message
        }
        ... on QueryHelloSuccess {
          data
        }
      }
    }