graphql-aws | Amazon AWS GraphQL API Server | AWS library

If you are not planning on having a single ReactJS client, then I don't think it's necessary to split the code base. The great thing about amplify, is that it will generate the queries, mutations, inputs, filters, and subscriptions based upon your annotated type schema. It'll place this in the front end src folder, so your front end developers only have to import { listAllTypes } from '/src/graphql/queries.js' and then use that query in their client code. There won't need to be separation, because your front end developers will only ever work within the project_root/src directory, and your backend developers will only ever work within the project_root/amplify/backend directory. Using a good git workflow will keep these concerns distinct between teams.