Systematic Troubleshooting

Your website loads, but checkout sometimes fails. Someone blames the network. Someone else wants to restart the database. Changing several things at once might hide the symptom without explaining what caused it.

Start with a precise observation: which request fails, for whom, since when, and with what error? Compare a failed request with a successful one and with the system's normal behavior. Follow the request through its dependencies. DNS resolution, connection establishment, TLS, application processing, and database access are different stages. Logs, metrics, and traces help locate where behavior first diverges. Form a testable hypothesis: ‘Checkout is waiting for an available database connection.’ Check pool usage and waiting time before changing pool limits. Evidence that contradicts the hypothesis is useful too. Begin with read-only checks. When a change is needed, keep it controlled, record the result, and have a rollback plan. During an outage, restoring service may take priority; investigate the underlying cause afterward. A restart that helps is evidence, not a complete explanation.