Every cost post here starts with some version of "nobody did anything wrong, and then the bill was $40k." Curious what yours looks like.
Drop the story — service, root cause, how you found out (Slack alert? Finance email? Console at 2am?). Doesn't have to be dramatic, the boring ones ("forgot to delete a NAT gateway," "left a dev cluster running for 3 months") are usually the most useful for everyone else to read.
I'll pull the best patterns into next week's post.