Who finds out first when a deploy breaks production, you or your users?

I spent months working in application support.

After every deployment, my job was to verify the release by hand: confirm the application was up, run the main flows, and document whatever broke.

What struck me over time was how often the pipeline had already reported success, and the first real signal that something was wrong came from a user, sometimes hours later.

I am curious how other teams here experience this.

When a deploy breaks something in production, who finds out first on your team, and how long does it usually take?

Is it a monitoring alert, a support ticket, or someone manually trying the flow?

And has anyone here managed to close that gap completely, or is some of it still manual where you work?