It’s 3am. PagerDuty is screaming. Checkout is failing for some customers but not others. You SSH into a box, tail the logs, and you’re greeted with a wall of INFO: processing request lines with no order ID, no user ID, no trace of which downstream service choked. Now you’re not debugging — you’re archaeology.
I’ve been on the other side of that night more times than I’d like to admit. And honestly, the difference between a 5-minute fix and a 3-hour outage is almost never the bug itself. It’s whether your logs told you anything useful. So let’s talk about what good logging actually looks like — not the textbook “log everything” advice, but the stuff that saves you when production is on fire.