public async Task<ActionResult> Index()
{
  await Task.Run(() => do some stuff);
  // Will schedule continuation on the synchronization context causing deadlock in ASP for .NET Framework,
  // but is legit in project type like console app or tests because synchronization context doesn't exist there.

  await Task.Run(() => do some stuff).ConfigureAwait(false); \
  // This is ok in all of the above cases. It will schedule continuation on a thread pool thread.
}