diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 0000000..a06fd4f
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2024-05-24 - Pre-calculating Search and Filter Values
+**Learning:** In highly iterated loops like `renderPDFs` and `createPDFCard` on large arrays, performing inline computations (e.g. concatenating strings, calling `toLowerCase()`, instantiating `Date` objects, using `Intl.DateTimeFormat`) drastically reduces performance.
+**Action:** Created a `prepareSearchIndex` method to be called immediately after the data array is populated (either via cache or fresh fetch) to map `_searchStr`, `_formattedDate`, and `_isNew` to each object. Then updated the filter logic to simply check `.includes()` against `_searchStr` and format logic to use the pre-calculated formats, reducing repeated calculations and object instantiations.
diff --git a/script.js b/script.js
index 22f399d..9c1bc9e 100644
--- a/script.js
+++ b/script.js
@@ -416,6 +416,30 @@ async function syncClassSwitcher() {
     renderSemesterTabs();
 }
 
+
+/* =========================================
+   PERFORMANCE UTILITIES
+   ========================================= */
+function prepareSearchIndex(data) {
+    const now = new Date();
+    const dateFormatter = new Intl.DateTimeFormat('en-US', {
+        year: 'numeric', month: 'short', day: 'numeric'
+    });
+
+    data.forEach(pdf => {
+        // Pre-calculate search string
+        pdf._searchStr = `${pdf.title} ${pdf.description} ${pdf.category} ${pdf.author || ''}`.toLowerCase();
+
+        // Pre-calculate formatted date
+        const uploadDateObj = new Date(pdf.uploadDate);
+        pdf._formattedDate = dateFormatter.format(uploadDateObj);
+
+        // Pre-calculate isNew flag (7 days)
+        const timeDiff = now - uploadDateObj;
+        pdf._isNew = timeDiff < (7 * 24 * 60 * 60 * 1000);
+    });
+}
+
 async function loadPDFDatabase() {
     if (isMaintenanceActive) return;
 
@@ -454,6 +478,7 @@ async function loadPDFDatabase() {
 
         if (shouldUseCache) {
             pdfDatabase = cachedData;
+            prepareSearchIndex(pdfDatabase);
             // --- FIX: CALL THIS TO POPULATE UI ---
             syncClassSwitcher();
             renderSemesterTabs();
@@ -477,6 +502,8 @@ async function loadPDFDatabase() {
             data: pdfDatabase
         }));
 
+        prepareSearchIndex(pdfDatabase);
+
         // --- FIX: CALL THIS TO POPULATE UI ---
         syncClassSwitcher();
         renderPDFs();
@@ -918,10 +945,15 @@ function renderPDFs() {
             matchesCategory = currentCategory === 'all' || pdf.category === currentCategory;
         }
 
-        const matchesSearch = pdf.title.toLowerCase().includes(searchTerm) ||
-            pdf.description.toLowerCase().includes(searchTerm) ||
-            pdf.category.toLowerCase().includes(searchTerm) ||
-            pdf.author.toLowerCase().includes(searchTerm);
+        let matchesSearch = true;
+        if (searchTerm) {
+            if (pdf._searchStr) {
+                matchesSearch = pdf._searchStr.includes(searchTerm);
+            } else {
+                const searchStrFallback = `${pdf.title} ${pdf.description} ${pdf.category} ${pdf.author || ''}`.toLowerCase();
+                matchesSearch = searchStrFallback.includes(searchTerm);
+            }
+        }
 
         // Update return statement to include matchesClass
         return matchesSemester && matchesClass && matchesCategory && matchesSearch;
@@ -994,9 +1026,7 @@ function createPDFCard(pdf, favoritesList, index = 0, highlightRegex = null) {
     const heartIconClass = isFav ? 'fas' : 'far';
     const btnActiveClass = isFav ? 'active' : '';
 
-    const uploadDateObj = new Date(pdf.uploadDate);
-    const timeDiff = new Date() - uploadDateObj;
-    const isNew = timeDiff < (7 * 24 * 60 * 60 * 1000); // 7 days
+    const isNew = pdf._isNew !== undefined ? pdf._isNew : (new Date() - new Date(pdf.uploadDate) < 7 * 24 * 60 * 60 * 1000); // 7 days
 
     const newBadgeHTML = isNew
         ? `<span style="background:var(--error-color); color:white; font-size:0.6rem; padding:2px 6px; border-radius:4px; margin-left:8px; vertical-align:middle;">NEW</span>`
@@ -1011,7 +1041,7 @@ function createPDFCard(pdf, favoritesList, index = 0, highlightRegex = null) {
     const categoryIcon = categoryIcons[pdf.category] || 'fa-file-pdf';
 
     // Formatting Date
-    const formattedDate = new Date(pdf.uploadDate).toLocaleDateString('en-US', {
+    const formattedDate = pdf._formattedDate || new Date(pdf.uploadDate).toLocaleDateString('en-US', {
         year: 'numeric', month: 'short', day: 'numeric'
     });