Working with Schema Stitching

import { stitchSchemas } from "@graphql-tools/stitch";

const gateway = stitchSchemas({
  subschemas: [
    { schema: usersSchema, executor: usersExecutor },
    { schema: ordersSchema, executor: ordersExecutor }
  ]
});

import { delegateToSchema } from "@graphql-tools/delegate";

resolvers: {
  Order: {
    customer: (order, _, ctx, info) => delegateToSchema({
      schema: usersSubschema, operation: "query",
      fieldName: "user", args: { id: order.customerId }, context: ctx, info
    })
  }
}

# In gateway:
extend type User {
  orders: [Order!]!
}