[RHSeeger]

> Using the 25% on-call rule, we can derive the minimum number of SREs required to sustain a 24/7 on-call rotation. Assuming that there are always two people on-call (primary and secondary, with different duties), the minimum number of engineers needed for on-call duty from a single-site team is eight: assuming week-long shifts, each engineer is on-call (primary or secondary) for one week every month.

How does this work in practice. If you're on call for the entire week, and the response time is expected to be no more than 13 minutes, are you expected to just... never leave your office (or home if you work from home) for a week straight?

I would expect on call, when it requires a specific response time, would be a normal 8 hour shift, and that's your 8 hours for the day. And you work on other stuff unless a call comes in, for which you drop whatever you're working on to deal with it.

For "I'm available by phone, but it could be an hour or two before I get to a computer if I'm needed", the week long shift makes a little more sense.

[zild3d]

(~60 person startup) we do roughly this, weekly on call rotation. If I'm going out, I bring my backpack or get coverage if having a backpack with you or nearby in the car is not feasible (have a thing I need to attend, can someone cover 7-9pm)

[RHSeeger]

That seems completely unmanageable to me (though, clearly not to you). Between picking up/dropping off my daughter, (food) shopping, making meals, going out to dinner, and so many other things; I'd fine it impossible to schedule a week straight where I could commit to responding within several minutes.

Honestly, I wouldn't feel comfortable asking anyone on my team to do it either. In my mind, if you're on call, then you're working (because you're committed to working being a priority over your personal life during that time). Which means the person should be paid for the entire time, and a week straight seems unreasonable.