A few weeks ago, I was reviewing the Amazon CloudWatch RUM dashboard for a web application I maintain. Page views were suspiciously low. After some digging, I opened the browser's DevTools on my machine and there it was: uBlock Origin was quietly blocking every request to dataplane.rum.eu-west-1.amazonaws.com . Our real user monitoring was blind to a non-negligible portion of our actual traffic. CloudWatch RUM is one of those AWS services that doesn't get the attention it deserves. But if you care about understanding how real users experience your application — page load times, JavaScript errors, HTTP failures, Web Vitals — it's genuinely valuable. Here's what the dashboard looks like out of the box: The problem is that ad blockers treat its data plane endpoint the same way they treat any third-party tracking domain: a request flying off to dataplane.rum.*.amazonaws.com looks exactly like telemetry that users might want to block.…