diff --git a/backend/src/index.ts b/backend/src/index.ts
index ddf68ab..5f3e86b 100644
--- a/backend/src/index.ts
+++ b/backend/src/index.ts
@@ -96,6 +96,7 @@ const upload = multer({
   dest: uploadDir,
   limits: {
     fileSize: 100 * 1024 * 1024, // 100MB limit
+    files: 1, // Only one file per upload
   },
   fileFilter: (req, file, cb) => {
     // Only allow .db files for SQLite imports
@@ -115,6 +116,22 @@ app.use(
 app.use(express.json({ limit: "50mb" }));
 app.use(express.urlencoded({ extended: true, limit: "50mb" }));
 
+// Log large requests for monitoring and debugging
+app.use((req, res, next) => {
+  const contentLength = req.headers["content-length"];
+  if (contentLength) {
+    const sizeInMB = parseInt(contentLength, 10) / 1024 / 1024;
+    if (sizeInMB > 10) {
+      console.log(
+        `[LARGE REQUEST] ${req.method} ${req.path} - ${sizeInMB.toFixed(
+          2
+        )}MB - Content-Length: ${contentLength} bytes`
+      );
+    }
+  }
+  next();
+});
+
 // Security middleware - Add security headers
 app.use((req, res, next) => {
   res.setHeader("X-Content-Type-Options", "nosniff");
diff --git a/frontend/nginx.conf b/frontend/nginx.conf
index 6ad2f0c..7dc06ea 100644
--- a/frontend/nginx.conf
+++ b/frontend/nginx.conf
@@ -12,6 +12,9 @@ http {
     gzip_vary on;
     gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
 
+    # Set maximum request body size to 50MB to handle large drawings with embedded images
+    client_max_body_size 50M;
+
     server {
         listen 80;
         server_name localhost;
@@ -29,6 +32,18 @@ http {
             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;
+            
+            # Buffer and timeout settings for large payloads
+            proxy_buffering on;
+            proxy_buffer_size 4k;
+            proxy_buffers 8 4k;
+            proxy_busy_buffers_size 8k;
+            client_body_buffer_size 128k;
+            
+            # Timeouts for large uploads (300 seconds)
+            proxy_connect_timeout 300s;
+            proxy_send_timeout 300s;
+            proxy_read_timeout 300s;
         }
 
         # WebSocket proxy for Socket.IO