When to give up on a company?

More of a 'sharing' moment, than a question.

I used to work for the largest healthcare organization in this area (12 years). I quit to pursue my own business a few years ago, at which time I gave them the appropriate advanced warning that I was leaving, I made sure the letter was carefully written so that I didn't burn any bridges when I left, and I thought all was good.

Two years later, and now I'm trying to get back into that organization but after applying to four different nursing positions, with interviews for each, I keep getting denied. No specific reason is ever given, I just get the generic:

"We were fortunate to have a number of excellent candidates apply for this position. While you have many fine skills and work experiences, after careful evaluation, we have decided to continue our search so that we can find a candidate whose background more closely matches the needs of the position."

Even for the exact same job I had before! Sure, my ACLS has elapsed, but my BLS is current, and not all of the positions require ACLS passing after starting.

Okay, fine. Being stubborn, I just tried logging into my profile on their system to look at things ... DELETED! :smackingf

At the last interview, I bluntly asked the HR representative if there was something on my chart that would be a red flag (attendance, sick time, etc). She specifically looked at my record and said "NO". There is nothing there that would cause concern.

So, I'm starting over ... same email, same password, I'll change up my resume (again!) and keep going (along with applying with other companies).

So, is the market tight, or what?