I worked at AWS (EC2 specifically), and the comment is accurate.
Engineers own their alarms, which they set up themselves during working hours. An engineer on call carries a "pager" for a given system they own as part of a small team. If your own alert rules get tripped, you will be automatically paged regardless of time of day. There are a variety of mechanisms to prioritize and delay issues until business hours, and suppress alarms based on various conditions - e.g. the health of your own dependencies.
End user tickets can not page engineers but fellow internal teams can. Generally escalation and paging additional help in the event that one can not handle the situation is encouraged and many tenured/senior engineers are very keen to help, even at weird hours.
Engineers own their alarms, which they set up themselves during working hours. An engineer on call carries a "pager" for a given system they own as part of a small team. If your own alert rules get tripped, you will be automatically paged regardless of time of day. There are a variety of mechanisms to prioritize and delay issues until business hours, and suppress alarms based on various conditions - e.g. the health of your own dependencies.
End user tickets can not page engineers but fellow internal teams can. Generally escalation and paging additional help in the event that one can not handle the situation is encouraged and many tenured/senior engineers are very keen to help, even at weird hours.