diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 0000000..5ad3160
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2024-05-04 - TaskGroup Serialization in Actors
+**Learning:** In Swift Concurrency, when an actor creates a `TaskGroup` and its subtasks call an `isolated` method on the same actor, execution is serialized on the actor's executor, destroying parallelism.
+**Action:** Mark computationally intensive or state-independent methods called from `TaskGroup` subtasks as `nonisolated` (like `NodeModulesScanner.findNodeModules`) so they run concurrently on the global pool.
diff --git a/Sources/Cacheout/Scanner/NodeModulesScanner.swift b/Sources/Cacheout/Scanner/NodeModulesScanner.swift
index 3ed4d8c..0306f0e 100644
--- a/Sources/Cacheout/Scanner/NodeModulesScanner.swift
+++ b/Sources/Cacheout/Scanner/NodeModulesScanner.swift
@@ -77,7 +77,8 @@ actor NodeModulesScanner {
             .sorted { $0.sizeBytes > $1.sizeBytes }
     }
 
-    private func findNodeModules(in directory: URL, maxDepth: Int, currentDepth: Int = 0) async -> [NodeModulesItem] {
+    nonisolated private func findNodeModules(in directory: URL, maxDepth: Int, currentDepth: Int = 0) async -> [NodeModulesItem] {
+        let fileManager = FileManager.default
         guard currentDepth < maxDepth else { return [] }
 
         var results: [NodeModulesItem] = []
@@ -120,7 +121,8 @@ actor NodeModulesScanner {
         return results
     }
 
-    private func directorySize(at url: URL) -> Int64 {
+    nonisolated private func directorySize(at url: URL) -> Int64 {
+        let fileManager = FileManager.default
         var total: Int64 = 0
         guard let enumerator = fileManager.enumerator(
             at: url,