diff --git a/frontend/nginx.conf b/frontend/nginx.conf
index d52bf24..0f39bb3 100644
--- a/frontend/nginx.conf
+++ b/frontend/nginx.conf
@@ -2,6 +2,8 @@ server {
     listen 80;
     server_name _;
 
+    client_max_body_size 200m;
+
     root /usr/share/nginx/html;
     index index.html;
 
@@ -10,9 +12,11 @@ server {
         try_files $uri $uri/ /index.html;
     }
 
-    # Proxy API requests to backend
+    # Proxy API requests to backend — use variable to defer DNS resolution
     location /api/ {
-        proxy_pass http://backend:8000;
+        resolver 10.43.0.10 valid=5s;
+        set $backend_upstream backend:8000;
+        proxy_pass http://$backend_upstream;
         proxy_set_header Host $host;
         proxy_set_header X-Real-IP $remote_addr;
         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
diff --git a/k8s/deploy.sh b/k8s/deploy.sh
index 03b4a5f..b8f704e 100755
--- a/k8s/deploy.sh
+++ b/k8s/deploy.sh
@@ -121,6 +121,8 @@ server {
     ssl_certificate_key /etc/letsencrypt/live/plfai.cn/privkey.pem;
     ssl_protocols TLSv1.2 TLSv1.3;
 
+    client_max_body_size 200m;
+
     location / {
         proxy_pass http://${backend_ip}:8000;
         proxy_set_header Host \$host;
@@ -146,6 +148,8 @@ server {
     ssl_certificate_key /etc/letsencrypt/live/plfai.cn/privkey.pem;
     ssl_protocols TLSv1.2 TLSv1.3;
 
+    client_max_body_size 200m;
+
     location /api/ {
         proxy_pass http://${backend_ip}:8000;
         proxy_set_header Host \$host;