Pagerduty puts alot of focus on reliability. They have redundant telephony providers and are hosted in multiple cloud provider data centers. You don't want you

Pagerduty puts alot of focus on reliability. They have redundant telephony providers and are hosted in multiple cloud provider data centers. You don't want your alerting service to go down with your service. When AWS goes down, Twilio, hipchat, and many other services can go down with it.