Learning: Instantiating Date objects and repeatedly lowercasing strings per item on every render loop causes significant and observable UI slowdowns in apps dealing with thousands of objects.
Action: When filtering or mapping data items, calculate derived variables (e.g., lowercased text (_searchStr), boolean checks (_isNew), preformatted dates (_formattedDate)) once during initialization/cache-load via a centralized prepareSearchIndex utility instead of recalcuating per-render. Additionally, skip redundant computations by utilizing early returns (if (!condition) return false;) within filter methods instead of combined boolean returns.