Debug Search and Stock Behavior in a Library Application

You inherit a library web application with book search, filtering, and stock management. Some pages show incorrect state and some searches return incomplete results. Explain how you would diagnose and fix the problems while using an AI assistant only to explain code or narrow the search area. ### Constraints & Assumptions The report describes an existing application but supplies no repository or exact failing example. Do not invent a specific root cause. The permitted AI workflow helps understand code; it does not directly supply or apply the final fix. ### Clarifying Questions What exact query, filter, and inventory change reproduces each symptom? What result is expected? Is the discrepancy visible in the backend response, the browser state, or both? ### What a Strong Answer Covers Reproduce each issue, trace the request through the application, reduce the failure, inspect backend semantics, and validate the smallest justified change with regression coverage. ### Follow-up Questions How can pagination or filter composition make search incomplete? How do you distinguish stale display state from an incorrect stock update? How would you verify an assistant's explanation of unfamiliar code?