Can you explain the concept of observability in systems and why it is needed?

Observability is the ability of a system to provide enough information about its internal state through external data to understand what is happening inside. In the context of software systems, this is usually achieved through logs, metrics, and traces.

Why is observability needed:

• Quick detection and diagnosis of problems.
• Understanding system behavior under load.
• Analyzing causes of failures and errors.
• Performance optimization.

Example: if in a Go application, metrics are collected using Prometheus and errors are logged, then when a service crashes, it is possible to quickly understand where exactly the error occurred and why.