diff --git a/listener/src/services/event-processing-queue.ts b/listener/src/services/event-processing-queue.ts
index e83cb16..4a1778a 100644
--- a/listener/src/services/event-processing-queue.ts
+++ b/listener/src/services/event-processing-queue.ts
@@ -63,6 +63,15 @@ export class EventProcessingQueue {
     processingTimes: [] as number[],
   };
 
+  // Metrics
+  private metrics = {
+    totalEnqueued: 0,
+    totalProcessed: 0,
+    totalSucceeded: 0,
+    totalFailed: 0,
+    processingTimes: [] as number[],
+  };
+
   constructor(processor: EventProcessor, options?: EventProcessingQueueOptions) {
     this.processor = processor;
     this.maxConcurrency = Math.max(1, options?.maxConcurrency ?? DEFAULTS.maxConcurrency);
diff --git a/listener/src/services/notification-retry-queue.ts b/listener/src/services/notification-retry-queue.ts
index 39fc817..a9fa5a9 100644
--- a/listener/src/services/notification-retry-queue.ts
+++ b/listener/src/services/notification-retry-queue.ts
@@ -68,6 +68,15 @@ export class NotificationRetryQueue {
     processingTimes: [] as number[],
   };
 
+  // Metrics
+  private metrics = {
+    totalEnqueued: 0,
+    totalProcessed: 0,
+    totalSucceeded: 0,
+    totalFailed: 0,
+    processingTimes: [] as number[],
+  };
+
   constructor(notificationFn: NotificationFn, options?: RetryQueueOptions) {
     this.notificationFn = notificationFn;
     this.baseDelayMs = options?.baseDelayMs ?? DEFAULTS.baseDelayMs;