Logging, Monitoring and Observability
Production applications need more than error messages shown to users. Observability involves logs, metrics, traces, request identifiers, and meaningful error context.
A request ID can connect frontend-visible failures to backend logs. Structured logs are easier to search and analyze than arbitrary strings.
Never log passwords, access tokens, session secrets, payment data, or unnecessary personal information.
Avoid Sensitive Logs
Production logs frequently have broader access than application databases. Treat logging as a data-security boundary.
Structured Logging
logger.info({
event: 'product_created',
requestId,
userId,
productId
});💡 Structured fields make production logs easier to search and correlate.
Key Takeaways
- Use structured logs and correlation IDs.
- Monitor both errors and performance.
- Never log secrets or unnecessary sensitive data.