If you don’t hear back from an interviewer right away, don’t follow up again until after the interviewer’s deadline has passed. If the date passes and you still haven’t heard anything, send a brief follow-up to remind the interviewer about your qualifications and interest in the open job. After that first follow-up, you can follow-up again every 1-2 weeks up to two more times for a total of three follow-ups. If you still haven’t heard back, you should move on.