For me personally, there's no possible way that a company can correctly factor on-call costs into my salary, because the on-call costs are based on what I am do

For me personally, there's no possible way that a company can correctly factor on-call costs into my salary, because the on-call costs are based on what I am doing at the time. You'd have to pay me a biblically large multiplier on my base salary to get me to pick work over my kids or wife. My kids aren't going to remember that I made a few thousand bucks by ducking out halfway through an important-to-them event. My wife is sure as shit ain't going to forgive me _or you_ if you call me into work in the middle of some adult time. And the cost for you to make sure that I'm not participating in such activities and am available to work on very short notice is...well, it's the exact same number as if you had interrupted such activities. If you really need the coverage in the middle of the night, hire more engineers whose normal 8-ish hour shifts are during the night? Can't afford to? Perhaps you're not so good at business then. Better yet, stop building a fucking house of cards that can topple your company if it wobbles a little bit. If your systems going down for a few hours can take down your company, outside of some exceptional circumstances, that's a failure on your part.