diff --git a/synkronus-portal/Dockerfile b/synkronus-portal/Dockerfile
index 960fc9179..5d254de16 100644
--- a/synkronus-portal/Dockerfile
+++ b/synkronus-portal/Dockerfile
@@ -23,6 +23,7 @@ FROM nginx:alpine
 COPY --from=builder /app/dist /usr/share/nginx/html
 
 # Copy custom nginx configuration for SPA routing
+# Backend API: http://demo.synkronus.cloud
 RUN echo 'server { \
     listen 0.0.0.0:80; \
     listen [::]:80; \
@@ -32,17 +33,22 @@ RUN echo 'server { \
     location / { \
         try_files $uri $uri/ /index.html; \
     } \
-    # Proxy API requests to backend \
+    # Proxy API requests to backend (demo.synkronus.cloud) \
     location /api { \
         rewrite ^/api(.*)$ $1 break; \
         proxy_pass http://demo.synkronus.cloud; \
         proxy_http_version 1.1; \
         proxy_set_header Upgrade $http_upgrade; \
         proxy_set_header Connection "upgrade"; \
-        proxy_set_header Host $host; \
+        proxy_set_header Host demo.synkronus.cloud; \
         proxy_set_header X-Real-IP $remote_addr; \
         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; \
         proxy_set_header X-Forwarded-Proto $scheme; \
+        proxy_set_header X-Forwarded-Host $host; \
+        proxy_connect_timeout 60s; \
+        proxy_send_timeout 60s; \
+        proxy_read_timeout 60s; \
+        proxy_buffering off; \
         client_max_body_size 100M; \
     } \
 }' > /etc/nginx/conf.d/default.conf
diff --git a/synkronus-portal/src/pages/Dashboard.tsx b/synkronus-portal/src/pages/Dashboard.tsx
index 0794b431f..5451f98c7 100644
--- a/synkronus-portal/src/pages/Dashboard.tsx
+++ b/synkronus-portal/src/pages/Dashboard.tsx
@@ -230,7 +230,7 @@ export function Dashboard() {
     try {
       const [info, healthResponse] = await Promise.all([
         api.get<SystemInfo>('/version').catch(() => null),
-        fetch(`${import.meta.env.DEV ? '/api' : 'http://localhost:8080'}/health`).catch(() => null)
+        fetch(`${import.meta.env.VITE_API_URL || '/api'}/health`).catch(() => null)
       ])
       if (info) setSystemInfo(info)
       
@@ -355,7 +355,7 @@ export function Dashboard() {
         xhr.addEventListener('error', () => reject(new Error('Network error: Upload failed')))
         xhr.addEventListener('abort', () => reject(new Error('Upload was cancelled')))
 
-        const apiBaseUrl = import.meta.env.VITE_API_URL || (import.meta.env.DEV ? '/api' : 'http://localhost:8080')
+        const apiBaseUrl = import.meta.env.VITE_API_URL || '/api'
         const uploadUrl = `${apiBaseUrl}/app-bundle/push`
         xhr.open('POST', uploadUrl)
         if (token) {
@@ -400,7 +400,7 @@ export function Dashboard() {
     setError(null)
     setSuccess(null)
     try {
-      const apiBaseUrl = import.meta.env.VITE_API_URL || (import.meta.env.DEV ? '/api' : 'http://localhost:8080')
+      const apiBaseUrl = import.meta.env.VITE_API_URL || '/api'
       const token = localStorage.getItem('token')
       
       const response = await fetch(`${apiBaseUrl}/dataexport/parquet`, {
@@ -1334,7 +1334,7 @@ export function Dashboard() {
                         <div className="info-content">
                           <h3>API Endpoint</h3>
                           <p style={{ fontSize: '13px', fontFamily: 'monospace', wordBreak: 'break-all' }}>
-                            {import.meta.env.VITE_API_URL || (import.meta.env.DEV ? '/api' : 'http://localhost:8080')}
+                            {import.meta.env.VITE_API_URL || '/api'}
                           </p>
                         </div>
                       </div>
diff --git a/synkronus-portal/src/services/api.ts b/synkronus-portal/src/services/api.ts
index 6f5eb14d1..c13276de6 100644
--- a/synkronus-portal/src/services/api.ts
+++ b/synkronus-portal/src/services/api.ts
@@ -6,8 +6,10 @@ const getApiBaseUrl = () => {
   if (import.meta.env.VITE_API_URL) {
     return import.meta.env.VITE_API_URL
   }
-  // Use proxy in development, direct URL in production
-  return import.meta.env.DEV ? '/api' : 'http://localhost:8080'
+  // Use /api proxy in both development and production
+  // In development: Vite dev server proxies /api to backend
+  // In production: Nginx proxies /api to http://demo.synkronus.cloud
+  return '/api'
 }
 
 const API_BASE_URL = getApiBaseUrl()