Engineering · Published August 18, 2026
Frontend Monitoring: Finding Out Before the White Screen
Users will not tell you the page is broken, they just leave. Monitoring has to be in place before launch.
We once got a call from a client saying the system would not open. A third-party script had failed to load and blanked the page. The error had been happening for six hours and we had no idea.
Collect at least four kinds of signal
Errors: JavaScript exceptions, failed assets and API failures, with route and browser version attached.
Performance: first paint and average API latency, grouped by release and region so regressions stand out.
Behaviour: clicks and navigation along key paths, enough to reconstruct what happened before the error.
Environment: network type, screen size and whether an ad blocker is active.
Practical advice
Use an existing platform first. Building your own monitoring costs far more than small teams expect.
Set thresholds: twenty errors of the same type within five minutes should page the team, not wait for a daily report.
After every incident, add one monitoring rule so the same class of failure never stays silent again.
Monitoring is not about pretty dashboards. It is about turning 'the user found it' into 'we found it first'.
Want to apply these ideas to your project?
We are happy to go deeper into implementation details, or to discuss the specific questions you are facing.
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