Automation
If you need to do something millions of times a day it needs to be repeatable and, ideally, idempotent. While it’s technically possible to get enough people in your system in a Mechanical Turk mechanism, in most cases what you want to do is truly automate the task.
The trick though, as, @Kelsey Hightower said the other day on the art of agile development book club is that “automation is a byproduct of understanding.”
You should listen to him explaining, but the basic idea is that first you understand what you need to do, then you figure out how to automate it. And the hard part is getting the understanding. Not just the knowledge of the steps you took. That’s the easy part. You also need to do the hard part, understanding why those steps, and why in that specific order.
It’s only after you have that understanding that you can really automate something. Without it you can execute the steps, and probably even notice and acknowledge failures along the way. But you can’t really understand the reason behind the failures. Which means you can’t do anything about them. Instead of automation, you’ve got a self-executing runbook. That’s a great place to start, and it might be enough for a while, but it’s not really an automated system.
An automated system understands your intent. In understands the goal you’re trying to achieve and helps you achieve it. It adapts around errors and delays. It figures out how to get from current state to the desired state. It notices deviations and corrects for them as well. And that gets into promise theory, which is a story for another day.