Creating Tags for External Dependencies in Context

interface UserService {
  getUser(id: string): Effect.Effect<never, Error, User>
}

const UserStore = Context.Tag(UserService)

const DDBUserStore = Layer.effect(
  Effect.gen(function* (_) {
    const config = yield* _(UserStoreConfig)
    const ddbClient = yield* _(DynamoDBClient)

    return UserStore.of({
      getUser: () => {
        ...
      }
    })
  })
)