title: How to improve the performance of a REST call which internally other REST calls
body: <p>I am creating an endpoint which retrieves me some data and in this call it calls 3 different REST calls and due to this it hampers the performance of my application.</p>
  
  <pre><code>My Endpoint Code:
  
   1. REST call to get the userApps()
   2. iterate over userAPPs
      2.1 make REST call to get the appDetails
      2.2 make use of above response to call the 3rd REST call which returns list.
      2.3 iterate over the above list and filter out the required fields and put it in main response object.
   3.return response
  </code></pre>
  
  <p>So, this much complexity hampers the performance.</p>
  
  <p>I have tried to add the multithreading concept but the time taken by normal code and multi threading is almost same.</p>
  
  <p>Condition is like, We can not modify the 3 external REST calls to support the pagination.</p>
  
  <p>We can not add the pagination because we don't have any database. 
  Is there any solution?</p>