From logs to insights: building observability into your stack

Observability isn't just logging; it's the combination of metrics, logs, and traces. Metrics tell you what happened (request count, error rate, latency). Logs tell you why (error messages, stack traces). Traces show you how requests flow through your system.

Start with the metrics that matter to your business: request latency, error rate, and resource utilization. Set alerts on these metrics to catch issues before customers report them.

Use structured logging (JSON format) instead of text logs. Include request IDs to correlate logs across services, include stack traces for errors, and avoid logging sensitive data like passwords or tokens.

Implement distributed tracing if you have microservices. Tools like Jaeger help you see exactly which services are slowing down requests and where errors occur.