Bundle multiple asynchronous calls which helps with performance.

Async Await with WhenAll.cs

var testRepo = new TestRepo();
//var start = DateTime.Now;
var t1 = testRepo.Task1();
var t2 = testRepo.Task2();
int[] r = await Task.WhenAll(t1, t2);
//var end = (DateTime.Now - start).Seconds;
return new int[] { r[0], r[1] };

/***************************/
public class TestRepo
{
  public Task<int> Task1()
  {
    var t = Task.Run<int>(() =>
    {
      Thread.Sleep(2000);
      return 20;
    });
    return t;
  }
  public Task<int> Task2()
  {
    var t = Task.Run<int>(() =>
    {
      Thread.Sleep(5000);
      return 50;
    });
    return t;
  }
}