Async Reactive operation with fallback observable

ProfileController.kt

//...elided package, class and imports...//
@RequestMapping("/profiles", method = arrayOf(RequestMethod.GET))
fun getUserByEmail(
        @RequestParam(value = "email") email: String,
): DeferredResult<ResponseEntity<Profile>> {

    val result = DeferredResult<ResponseEntity<Profile>>()
    val uriBuilder = ServletUriComponentsBuilder
            .fromCurrentRequest()
            .path("/{uuid}")

    // Setup the fallback steps for getting the user from the userService,
    // creating a new profile, and storing the profile
    val newProfile = Observable.defer { userService.fetchUser(email) }
            .onError { result.setErrorResult(ResponseEntity.badRequest().build()) }
            .map { user -> Profile(UUID.randomUUID(), "primary_email", user.email, "email", "basic") }
            .map { profile -> profileRepository.save(profile) }

    // 1) Check if we have the users profile
    val existingProfile = profileRepository.findByNameAndValue("primary_email", email).subscribeOn(Schedulers.io())
    existingProfile
            .onErrorResumeNext(newProfile) // 2) We don't have it, so let's get it as newProfile
            .map { profile -> createResponseEntity(profile, uriBuilder.buildAndExpand(profile.uuid).toUri()) }
            .subscribe { response -> result.setResult(response) }

    return result
}