Unfortunately it's also not just resources that cost money. A couple of fun billing surprises I've seen. 1. A bug in a system that uploaded quite a lot of da

Unfortunately it's also not just resources that cost money. A couple of fun billing surprises I've seen. 1. A bug in a system that uploaded quite a lot of data to Amazon S3 caused it to hit the S3 API to the tune of about $10K/day. Because AWS billing is usually 2-3 days lagged, it took us 3 days to notice. We fixed it right away once we found it. Goodby to that $30K. 2. An engineer did an Athena query that happened to walk many TB of data. And they unknowingly did it in us-west-2, but the data was in us-east-1. So that resulted in a cross region transfer to the tune of $10K for that single query.