An unfortunate fact of my career is that 24x7 support has been a general assumption of my consulting roles more often than not (read: Weekend Warrior).
One one such contract we fortunately had an on-call rotation which meant I wasn't stuck doing the support every night and weekend, however because of how the project was run there was nearly a guarantee that you would get a call in the middle of the night when you were on call, typically once you had finally fallen asleep.
The biggest problem with this contract is that you would be 2 hours into a debugging session with the engineer who woke you up before finding out that the issue was caused by an alert on a test system and wasn't actually impacting anyone - not users, not developers, not testers. Nobody was trying to use the system at that time and it was 4am and I was tired.
There were no contractual obligations to address these non-production issues but there seemed to be a communication issue on this point with the overnight operations staff. This was a frequent enough occurrence that I learned to answer my phone by asking "Is this a production issue?"
To this day I verify the environment and the users impacted as the first step when triaging support issues.
