What a dead-letter pile is trying to tell the morning shift

A dead-letter pile grows for three ordinary reasons, and mixing them on one slide makes the morning stupid.

Some records arrive with yesterday’s shape: a field renamed upstream, a date that is now a string. That is schema drift leaking in the night. Some arrive twice because a rerun did not mark the first batch spent. Some never find the next system because the handoff job was killed and not restarted.

We stain the pile by cause, not by count. A thousand duplicates can be one decision at 02:15. Twelve records with a broken shape can be a quieter disaster, because they will keep arriving until someone talks to the source.

Operators often apologise for the pile as if it were untidiness. It is evidence. If your crew is ashamed to show it, the recap will be late and the director will hear a softer story than the night deserves.

When you write to the desk, say whether the pile is opened at breakfast or left until Friday. That habit belongs on the sheet.