diff --git a/backend/utils/tos_client.py b/backend/utils/tos_client.py
index b5dd774..8bc2d85 100644
--- a/backend/utils/tos_client.py
+++ b/backend/utils/tos_client.py
@@ -1,7 +1,6 @@
 """Volcano Engine TOS file upload utility using official TOS SDK."""
 
 import uuid
-import tos
 from django.conf import settings
 
 
@@ -17,6 +16,7 @@ _client = None
 
 
 def get_tos_client():
+    import tos
     global _client
     if _client is None:
         endpoint = settings.TOS_ENDPOINT.replace('https://', '').replace('http://', '')
diff --git a/web/src/store/generation.ts b/web/src/store/generation.ts
index 81469c1..9534861 100644
--- a/web/src/store/generation.ts
+++ b/web/src/store/generation.ts
@@ -81,7 +81,7 @@ function startPolling(taskId: string, frontendId: string) {
     } catch {
       // Silently continue polling on error
     }
-  }, 5000);
+  }, 3 * 60 * 1000); // 3 minutes
 
   pollTimers.set(frontendId, timer);
 }