When should I follow up after an interview?
Usually when an employer says you will hear from them after an interview, it means you will ONLY hear from them if you were selected. They normally don't waste time calling folks they didn't select, sometimes they do but many times they don't. They figure you can get the hint when you don't receive the call in the time they said they would call.
Here's the thing Most companies will only call you if you get the job, they won't take the time to call people who don't meet the company requirements.When they say "we'll call you in _______" it's merely them being courteous, they don't have the time to call back 50-200 people letting them know they didn't get the job. They said 3-4 days right? That would put you at Thursday, and you have to take in additional time, in case that manager/supervisor wasn't in on a specific day. I'd call in Monday, but really you need to prepare yourself that you may have not gotten the job.
If the company took that long to contact you for the interview after you applied, then obviously they are not in the same rush you are. Respect their timeline. Trust me, whether you follow up or not, if you're selected for the role, they WILL be contacting you. If you're not, then they likely won't.
Where are you located? It is possible some people did not get into work due to the weather
Phone or email and ask for feedback re the interview and position
DR + Mrs Bears face
Unless told to then you don't. If they want you they contact you. People following up is the biggest time waster in my day.
Send them an email any time, But if they don't get back to you next week, they probably aren't going to