The part that stood out to me was "the bill is the system, expressed in dollars."

I've noticed this becoming especially obvious with AI features. A lot of teams carefully think about latency, reliability, and UX, but don't realize they've accidentally designed a workflow where one user action fans out into multiple model calls, retrieval steps, evaluations, and traces.

Nothing looks expensive when you review each component individually. The surprise comes when you follow a single request from start to finish and realize how much infrastructure is participating in that one interaction.

It feels like we're reaching a point where architecture diagrams should include cost flow alongside data flow. Not because every decision needs to be optimized, but because some cost shapes only become visible once the system starts operating at scale.