At a previous employer we had a pair on call for each of: front end, back end, and infra. We had on-call lasting from Monday midday - Friday midday. Handing off to a "weekend on-call" from the same pool of people from Friday midday to Monday midday. Weekend on-call paid 100 per day, weekday on-call paid 50 per day. You were generally expected to take normal time "off" (but still on call) if paged off hours. Many people would still work if it was just a blip (rare).

I thought this was a pretty good system and despite the cycles being shorter, we had enough engineers to fill a rotation pretty well so that at most you were on call once a month, alternating months between weekend and weekday on-call cycles.

I still do not enjoy being forced into on call and wish I could opt-in. We traded weeks a lot but with smaller rotations or really finicky paging its awful. I still have a sinking feeling in my gut when I hear the work phone ringtone from somebody else's phone in public, and murphy's law definitely applies to being on call -- you always get paged the minute after your beer gets delivered at a restaurant.