How do I switch off from being always on call?

You can make almost anything dependable, but the cost is that a part of you is always braced for the pager, even in your own quiet hours. That low hum of vigilance is exhausting precisely because it never fully stops. Your body stays on watch even when your shift is over. The systems can be reliable without you being permanently on alert. If everything depends on your personal watchfulness, that is not a resilient system; it is a fragile one leaning on you. Building things that hold without your constant attention is not laziness. It is the real goal. Pick one thing that currently only your vigilance catches, and turn it into an automated alert or a shared rotation. Move one worry out of your head and into the system where it belongs. You made the machines reliable. Now let them carry some of the watch, so you are allowed to rest.