Short version : time to move on.
The first time I fail to fix it within 20 minutes, I will be fired.
The sort of condition written by a megalomaniac with no technical knowledge at all. Problem solving simply does not work this way.
Your second sign you are working for an insane organization and, again, time to start looking for a new job. It can only get worse at this organization after this.
There is no rotation or anyone else looking out.
Which is insanity.
Mission critical 24/7/365 systems cannot be managed or monitored by one person without rotation or backup. It is impossible.
For me this is the absolute clincher that this organization is run by con artists, chancers and/or idiots.
Get out ASAP.
At best this was a sign that the lunatics have taken over the asylum, or worst it's a sign that they're running out of money (!) and, from experience, the next things to happen will be people not being replaced, endless non-optional overtime, maybe even wages not being paid on time.
I cannot tell you how many alarm bells this rings for me.
Run to the exit as soon as you find somewhere sane sounding. Don't walk - make this your priority.
I work in IT and was recently promoted to a higher position. While I was okay with the responsibilities outlined when I accepted the promotion last week,
Accepted in writing by signing a contract ? If that's what you did then they can (*legally) only apply the terms in the contract at that time almost everywhere ( note : IANAL ).
today I learned it comes with 24/7/365 on-call to monitor mission critical systems.
Being on-call should have been discussed and agreed (!) before taking the promotion or even being offered the position.
Being on-call is not unreasonable is itself for a senior position, but being on call should not be a "surprise extra" never discussed and agreed to.
This is the first sign that this company is a disaster zone for your personal sanity. I would already be looking for a new job elsewhere.
What the hell do I do now ?
Polish your CV and get a new job ASAP.
The longer you stay the more stressful this madness will become. It's time to move on.
The demands are so extremely unreasonable that talking to them is a waste of time (IMO). They'll most likely try to jolly you along and then you'll start getting the calls at all hours and that's a problem.
I feel like I just got bait and switched and I want to go back to my old position. Frankly I have half a mind to leave.
Forget the old position - it's the same company and I suspect even if you try and stay at your old position, they will try and pressure you to take on the work anyway ( "just temporarily" ).
Staying is not an option, IMO.
I feel like I'm expected to give my life to a company that doesn't treat its employees well. Am I being unreasonable?
You are being reasonable.
Is this just a fact of life for a career in IT?
Yes, you can be on-call in senior roles (and even junior roles) and you may get the call in the middle of the night. If employers can get you to go along with that (unpaid) they will. You have to be strict with them or some managers will exploit your willingness to help out in emergencies.
It's normally done like this :
- You help out on one emergency.
- The next time you say "no", they will say "but we were counting on you. You did it before !".
Some people fall for this, some don't. If you're not explicitly on call (and getting remuneration to justify that) then you say, sorry, I'm doing personal stuff and you can't expect me to be available just anytime.
24/7 operations need a 24/7 shift roster. It's that simple. Anyone operating 24/7 as if it was 9-5 is a cowboy outfit.
Mission critical means a company should pay for enough staff to reasonably cover it.
Note there is a difference between the odd call e.g. once a month on the basis of "fix as soon as you can" and what these madmen are expecting. We've all had the three straight days living on coffee and pizza thing - it should be a rare exception. These conditions you have been given are beyond any rational or reasonable expectation - a long way beyond.
Companies not doing this are places you leave ASAP. It either means managers will cut any corner and don't care about staff and/or that they are financially in trouble. In any case you leave as soon as you have a new job and you make that happen as soon as practical.