Tracking Custom Exceptions in Web apps

What is CustomException in Web apps?

CustomException represents an error that was explicitly caught by the developer using a try/catch block, but was intentionally sent to Appxiom for monitoring purposes.

Why it matters

Just because an error was caught and handled gracefully (e.g., showing a fallback UI to the user instead of crashing) does not mean it should be ignored. Teams need visibility into how often these fallbacks are triggering in production.

Why does this happen?

Business Logic Validation

A user submits a form that passes frontend validation but fails a complex backend business rule. The developer catches the error and logs a CustomException to track the frequency of this specific business logic failure.

Graceful Degradation

If a non-critical third-party service (like a recommendation engine) times out, the developer catches the error, hides the widget, and logs the CustomException so engineering knows the integration is degraded without the user ever noticing a crash.

How to fix it using Appxiom

• Analyze stack trace: Appxiom provides the exact minified and source-mapped stack trace pointing directly to the line of JavaScript/TypeScript code that triggered the issue.
• Trace activity trail: The activity trail provides a chronological list of user interactions (clicks, route changes) and network calls that occurred right before the issue, helping developers reproduce the exact user journey.