A Developer's Guide to Performance Budgets

A performance budget only works if it fails loudly. A number in a doc is a wish; a number in CI is a constraint.

Pick two or three metrics that map to how users experience the app — largest contentful paint, interaction latency, and JavaScript transferred — and set thresholds slightly below where you are today.

Then make regressions cheap to diagnose. A per-PR bundle diff turns 'the app feels slower' into 'this dependency added 180kb', which is a conversation a team can actually resolve.