Our AWS bill crossed $180K in a single month. We had Datadog. We had CloudWatch dashboards. We had a PagerDuty integration, three runbooks, and a Grafana board that took an intern two weeks to build. We had observability . What we didn't have — what I didn't realize we were missing until our CFO sent a Slack message on a Tuesday afternoon — was any idea which product feature was responsible for which dollar. She didn't ask why our p99 latency was 230ms. She asked: "Which feature drove the $34K jump in compute costs last month?" I had no answer. This is that story. And if you're running a B2B SaaS product with more than a handful of microservices and an AI component or two, I'd bet it's your story too — you just haven't hit the Tuesday Slack message yet. The false confidence of having "monitoring" Here's the trap: modern observability tooling is extraordinarily good at answering infrastructure questions . It is almost completely blind to product questions .…