diff --git a/.jules/bolt.md b/.jules/bolt.md
index ba67a71..c425e3c 100644
--- a/.jules/bolt.md
+++ b/.jules/bolt.md
@@ -3,3 +3,7 @@
 ## 2026-07-16 - [O(N*M) Nested Loop Lookups in Grading Engines]
 **Learning:** In interactive scenarios (such as Bid Elevator and STR Triage), grading engines frequently iterate over user decisions and match them against scenario properties (like keywords or search terms). Performing `array.find()` inside loop bodies or filter predicates results in costly O(N*M) lookups.
 **Action:** Convert arrays to `Map` lookups before entering loops/nested scans. Mapping keys once in O(M) time enables O(1) lookups during execution, transforming the time complexity of the grading logic to O(N + M).
+
+## 2026-07-20 - [Scoping Lesson Progress Queries to Visible Lessons]
+**Learning:** When loading the user's lesson progress on general dashboard pages (e.g., Courses Catalog, Student Dashboard, or Certificate pending lists), querying `db.lessonProgress` without filtering `lessonId` causes the database to scan and return the entire student's progress history across all courses. As courses and lesson count scale, this results in bloated database payloads and high memory/CPU usage.
+**Action:** Always extract the list of visible lesson IDs first and use `lessonId: { in: lessonIds }` to scope the database queries. This keeps query results lightweight and bounded.
diff --git a/src/app/(dashboard)/courses/[courseSlug]/certificate/page.tsx b/src/app/(dashboard)/courses/[courseSlug]/certificate/page.tsx
index 3640169..59e7827 100644
--- a/src/app/(dashboard)/courses/[courseSlug]/certificate/page.tsx
+++ b/src/app/(dashboard)/courses/[courseSlug]/certificate/page.tsx
@@ -194,13 +194,21 @@ async function PendingLessons({
     take: 50,
   });
 
+  const allLessonIds = allLessons.map((l) => l.id);
   const completedSet = new Set(
-    (
-      await db.lessonProgress.findMany({
-        where: { userId, status: 'COMPLETED', deletedAt: null },
-        select: { lessonId: true },
-      })
-    ).map((p) => p.lessonId),
+    allLessonIds.length > 0
+      ? (
+          await db.lessonProgress.findMany({
+            where: {
+              userId,
+              lessonId: { in: allLessonIds },
+              status: 'COMPLETED',
+              deletedAt: null,
+            },
+            select: { lessonId: true },
+          })
+        ).map((p) => p.lessonId)
+      : [],
   );
 
   const pending = allLessons.filter((l) => !completedSet.has(l.id)).slice(0, 8);
diff --git a/src/app/(dashboard)/courses/page.tsx b/src/app/(dashboard)/courses/page.tsx
index 1d0c6c3..2d02c00 100644
--- a/src/app/(dashboard)/courses/page.tsx
+++ b/src/app/(dashboard)/courses/page.tsx
@@ -37,11 +37,19 @@ export default async function CoursesIndexPage() {
     },
   });
 
-  // Get user's lesson progress
-  const lessonProgress = await db.lessonProgress.findMany({
-    where: { userId: user.id, deletedAt: null },
-    select: { lessonId: true, status: true },
-  });
+  const allLessons = courses.flatMap((c) => c.modules.flatMap((m) => m.lessons));
+
+  // Get user's lesson progress scoped to course lessons
+  const lessonProgress = allLessons.length > 0
+    ? await db.lessonProgress.findMany({
+        where: {
+          userId: user.id,
+          lessonId: { in: allLessons.map((l) => l.id) },
+          deletedAt: null,
+        },
+        select: { lessonId: true, status: true },
+      })
+    : [];
   const progressMap = new Map(lessonProgress.map((p) => [p.lessonId, p.status]));
 
   return (
diff --git a/src/app/(dashboard)/dashboard/page.tsx b/src/app/(dashboard)/dashboard/page.tsx
index 546298d..a91acae 100644
--- a/src/app/(dashboard)/dashboard/page.tsx
+++ b/src/app/(dashboard)/dashboard/page.tsx
@@ -30,16 +30,23 @@ export default async function DashboardPage() {
     },
   });
 
-  // Get user's lesson progress
-  const lessonProgress = await db.lessonProgress.findMany({
-    where: { userId: user.id, deletedAt: null },
-    select: { lessonId: true, status: true },
-  });
-  const progressMap = new Map(lessonProgress.map((p) => [p.lessonId, p.status]));
-
   // Compute aggregate stats
   const allLessons = courses.flatMap((c) => c.modules.flatMap((m) => m.lessons));
   const totalLessons = allLessons.length;
+
+  // Get user's lesson progress (scoped to course lessons to prevent massive payloads)
+  const lessonProgress = allLessons.length > 0
+    ? await db.lessonProgress.findMany({
+        where: {
+          userId: user.id,
+          lessonId: { in: allLessons.map((l) => l.id) },
+          deletedAt: null,
+        },
+        select: { lessonId: true, status: true },
+      })
+    : [];
+  const progressMap = new Map(lessonProgress.map((p) => [p.lessonId, p.status]));
+
   const completedLessons = allLessons.filter((l) => progressMap.get(l.id) === ProgressStatus.COMPLETED).length;
   const inProgressLessons = allLessons.filter((l) => progressMap.get(l.id) === ProgressStatus.IN_PROGRESS).length;