If I am guessing his company correctly, then most development teams indeed do their own pager duty with typical oncalls lasting one week. Some teams have extremely heavy ops load and have support people or even support teams that focus on doing ops and reducing op load.

There are several possible causes of such an unusually high ops load. Maybe it's a failing in that team (teams typically track operation load carefully, as it can serve as an early indicator of something in the team dynamics going wrong), that team might be under pressure from management to push out new features on a tight schedule (leaving less time to get things right, or to fix known issues), they may have had the unfortunate luck of inheriting a service written quick and dirty by one of the VP's favored "get shit done fast" teams (a problematic phenomenon that fortunately seems to be becoming less common), or it may just be the nature of their particular work for whatever reason.

I have seen teams with extremely high operation load get support teams based out of other timezones, so that 24/7 ops coverage can be done mostly by people working during their regional business hours. Why that hasn't been set up in his case, I cannot say.

There are many, many companies that provide customer-facing services that don't develop their own software in house and rely on vendors for all their systems. The TV services provided by telcos and cablecos are one example. Of all the "major" telcos in the world that provide a TV service, I only know of one that does anything in house.