The interviewer corrected: I wanted to hear about logging and system observability in the context of error handling.

Logging and observability in the context of error handling are key elements for quickly identifying and resolving issues in the system.

Error logging should be structured and contain sufficient information: error type, call stack, execution context, input data, and time of occurrence. This helps quickly understand the cause and localize the problem.

Observability includes metrics, traces, and alerts. Metrics (e.g., number of errors, response time) allow monitoring the system's state in real-time. Traces (distributed tracing) help trace the request path through microservices and identify bottlenecks or failures.

Example: when an error occurs in an API service, log details, increment the error counter in metrics, and create an alert if the error count exceeds a threshold. Tracing helps understand exactly which service and stage the failure occurred.

Thus, logging and observability ensure transparency of the system's operation and enable prompt response to errors.