I worked for a company where developers could opt in to on-call cover. Doing so meant you got some extra cash, and if you were called then you got so much for the first hour, then a different amount for each hour after that. Not being coy, I can’t remember the details.

I'm a pretty heavy sleeper, and would go to bed with my phone on silent, set to ring a long time before going to answerphone, and with my Apple Watch on my wrist. If my phone rang then my watch would buzz me awake, eventually. The only snag was if, in my sleep, I knocked the watch out of contact enough that it locked and wouldn’t buzz on calls, but in practice I was lucky enough that I never got a call when that happened.

Not that I was called often. The company had developers around the world so it was only if they needed some specific knowledge or skills. That meant that being on-call was mostly a fee to compensate for being available at short notice and not drinking, etc.

Ultimately they decided they weren’t getting enough calls to justify the cost of paying the on-call fees and scrapped the system, just relying upon whichever developers around the world were working.

They didn't for me - it meant my SO would wake me up after they'd been woken up.

I then started wearing headphones to bed so that I would hear the phone ring and not disturb them, but when you're rolling out of bed and hopping on a call at 3AM it's difficult.

What I seriously underestimated was the strain that being on-call can put on a relationship, it's a massive regret.