[amriksohata]

In the UK there are laws you can opt out of being asked to work more than a certain amount of hours. They company should have an out of hours plan but most experienced developers will know very few things get resolved in the middle hours of the night, things need testing, reviewing and sometimes the solution is not simple, it is better like you said to have ops staff that gather data and then pass it on when devs are in fresh, however if you have, say, a big international sale which is happening in another timezone then why not just pay staff as a one off to be around?