Thank you for sharing your experience. It is not one we would put in our "best practice" category. We are working to set better out going messages with the Hackerrank invitations as to when we will be able to follow up with the individual. Furthermore if you were given an email address for a recruiter and found them to be unresponsive, that is not ok by us and we will continue to look for the ways get more visibility to our recruiting leadership to remedy questions or concerns.