Every few years, the cloud cost world goes through a foundational shift. The AWS Cost and Usage Report became the de facto standard a decade ago, and an entire ecosystem of tools, dashboards, and pipelines grew on top of it. That ecosystem is now being asked to migrate. The FinOps Foundation's FOCUS specification has reached version 1.2, all three hyperscalers are publishing FOCUS exports, and AWS has signalled that CUR will eventually be deprecated for new use cases. The window to migrate cleanly is closing through Q2 2026. We have been running FOCUS migrations for customers since the 1.0 release and we want to share what we have learned. This is not a marketing piece. It is the engineering brief we wish we had at the start. The migration is doable, but it has more sharp edges than the official documentation suggests, and the teams that move first will avoid a painful crunch later. Why FOCUS 1.2 Matters and What It Changes FOCUS exists to solve a real problem.…