Performance Budget Monitor
Ship fast without shipping slow pages.
What changes when you build this
The gaps you're living with today,
and what this tool fixes.
Problems
- Bundle size creeps up 5-10 KB per sprint because no one checks until the quarterly audit
- P95 latency regressions ship to production and sit there for weeks before anyone opens a ticket
- Frontend and backend teams track performance in separate dashboards, so nobody sees the full picture
- Budget thresholds live in a wiki page that was last updated 6 months ago — alerts fire from different numbers
- Postmortem action items say "add a performance gate" but there is no system to enforce one
Solutions
- Every endpoint and bundle tracked against a declared budget in one table — no wiki needed
- Breach alerts fire within hours of a deploy, not weeks after users start complaining
- One dashboard covers frontend weight, API latency, and core web vitals across all services
- Thresholds are version-controlled rows, not scattered configs — change history is built in
- Platform team reviews a single weekly view instead of pulling data from three observability tools
Mistakes to avoid
These are the failure patterns teams hit most often
when building this.
Budgets set once and never revisitedFix: Schedule a quarterly review row in the budget table with an owner and a due date.
Budgets set once and never revisited
Fix:Schedule a quarterly review row in the budget table with an owner and a due date.
Alert fatigue from noisy thresholdsFix: Separate warning (within 10% of budget) from breach (over budget) and only page on breaches.
Alert fatigue from noisy thresholds
Fix:Separate warning (within 10% of budget) from breach (over budget) and only page on breaches.
No link between breach and deployFix: Join the budget_checks table to your deployments table so every breach shows which release caused it.
No link between breach and deploy
Fix:Join the budget_checks table to your deployments table so every breach shows which release caused it.
Frontend and backend tracked separatelyFix: Use a single metric_type enum that covers both latency and bundle size in the same table.
Frontend and backend tracked separately
Fix:Use a single metric_type enum that covers both latency and bundle size in the same table.
Metrics checked manually before releasesFix: Automate budget checks on every deploy via a CI webhook that writes results to the budget_checks table.
Metrics checked manually before releases
Fix:Automate budget checks on every deploy via a CI webhook that writes results to the budget_checks table.