Cloud Cost Anomaly Detection: How to Catch Surprise Bills Before They Hit

Cloud Cost Anomaly Detection: How to Catch Surprise Bills Before They Hit Cloud bills don't spike gradually. They spike overnight. A misconfigured NAT gateway starts routing all inter-AZ traffic inefficiently on a Friday. A data pipeline job enters an infinite retry loop on Saturday. A developer spins up a p3.8xlarge for a test and forgets to terminate it over a long weekend. By the time you find out, you've already burned through budget that wasn't allocated for it. The problem isn't that anomalies happen. The problem is the detection lag: most teams don't discover a cost spike until the invoice arrives 30 days later. With the right alerting in place, you catch the same spike in under 6 hours. This is the practical guide to setting that up. Why Cloud Bills Spike (And Why You Don't Find Out for 30 Days) The most common sources of surprise cloud bills fall into four categories. Data transfer charges are the least visible. Egress to the internet, cross-AZ traffic, and PrivateLink endpoin