Performance budgets that actually hold

Most teams write a performance budget once, celebrate, and then watch it erode one convenient exception at a time. The problem is rarely the number — it is that the number lives in a document instead of the build.

We treat budgets as tests. Bundle size, Largest Contentful Paint, and interaction latency each have a threshold that fails CI. A regression is a red build, not a retro item.

The discipline is uncomfortable at first. It is also the only version we have seen survive contact with a deadline.