If you do not get a response right away, wait till the interviewer’s deadline has passed. If you still do not hear anything, send a brief follow up note and remind the interviewer that how you fit the position well and your interest in the role. You should follow-up 2 more times with an interval of 7-10 days each. If you still do not get a response, it is most likely because you do not fit the role and you should apply for more opportunities in the portal.