what is the standard way to design a high throughput spring based web serivce with Async in mind - spring-boot

Question

I have a requirement to design spring-boot based webservice with #Async tags.
if the data return from server takes huge time how can i divide my webservice in multiple end points so that client does not have to wait for response from server.
i hv tried using three end points.
1. localhost:8080/start -> client will send request for data. (returs a uuid of requestnumber).
2. localhost:8080/checkprogress -> check for progress if data is ready at server.
3. localhost:8080/done/requestId -> return the data list
#ResponseBody
#GetMapping(value = "/start")
public ResponseEntity<String> start() {
String requestId = UUID.randomUUID().toString();
LOG.info("jobName" + requestId);
Job job = new Job("jobName" + requestId);
requestQueue.put(requestId.toString(), job);
service.submitWork(job);
return new ResponseEntity<String>(requestId, HttpStatus.ACCEPTED);
}
#ResponseBody
#RequestMapping(value = "/progress/{requestId}")
public ResponseEntity<String> fetchStatus(#PathVariable("requestId") String requestId) {
Job job = requestQueue.get(requestId);
if (job == null) {
return new ResponseEntity<String>("RequestId is either invalid or already served. requestId:" + requestId,
HttpStatus.BAD_REQUEST);
}
if (job.getState() == State.RUNNING || job.getState() == State.NEW)
return new ResponseEntity<String>(HttpStatus.NO_CONTENT);
if (job.getState() == State.DONE)
return new ResponseEntity<String>(HttpStatus.OK);
return null;
}
#ResponseBody
#RequestMapping(value = "/done/{requestId}")
public ResponseEntity<Object> done(#PathVariable("requestId") String requestId) {
LOG.info("removing requestId:" + requestId);
Job job = requestQueue.get(requestId);
if (job == null) {
return new ResponseEntity<Object>("RequestId is either invalid or already served. requestId:" + requestId,
HttpStatus.BAD_REQUEST);
}
// ResponseEntity<Object> response = new ResponseEntity<Object>(job.getList(),
// createHeader(HttpHeaders.ACCEPT, MediaType.APPLICATION_JSON_VALUE), HttpStatus.OK);
ResponseEntity<Object> response = new ResponseEntity<Object>(job.getListOfSecurities(),
createHeader(HttpHeaders.ACCEPT, MediaType.APPLICATION_JSON_VALUE), HttpStatus.OK);
requestQueue.remove(requestId);
return response;
}
is there a better way of doing above thing in a Standard way in spring-boot java8 application please?