We're running a multi-account setup with AWS Organizations. The centralized billing is fine, but trying to actually charge back CI/CD costs to the correct dev teams is a mess.
The main CI account runs the runners, but all the compute for builds happens in the workload accounts via cross-account roles. So the compute bill lands in the workload accounts, but the real cost driver is the pipeline activity from the central account. AWS tags are supposed to solve this, but they don't propagate cleanly across accounts for these cross-account resources. We're left with fragmented cost data.
I've tried Cost Explorer and the CI tools' own dashboards. Neither gives a complete picture. The result is fuzzy allocation and teams arguing about whose $15k EC2 spike it really was.
Is this just a fundamental flaw in this setup, or has anyone found a way to make the numbers line up?