diff --git a/core/templates/tree/react_express/api/app.js b/core/templates/tree/react_express/api/app.js
index 7bb10278..7c72a309 100644
--- a/core/templates/tree/react_express/api/app.js
+++ b/core/templates/tree/react_express/api/app.js
@@ -1,4 +1,6 @@
 import path from 'path';
+import { existsSync } from 'fs';
+import { fileURLToPath } from 'node:url';
 
 import cors from 'cors';
 import express from 'express';
@@ -9,6 +11,9 @@ import { authenticateWithToken } from './middlewares/authMiddleware.js';
 {% endif %}
 import apiRoutes from './routes/index.js';
 
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 // Set up Express app
 const app = express();
 
@@ -29,10 +34,22 @@ app.use(authenticateWithToken);
 
 app.use(apiRoutes);
 
-app.use(express.static(path.join(import.meta.dirname, "..", "dist")));
+app.use(express.static(path.join(__dirname, "..", "dist")));
 
-// Assume all other routes are frontend and serve pre-built frontend from ../dist/ folder
+// Assume all other routes are frontend
 app.get(/.*/, async (req, res) => {
+    // Try to serve pre-built frontend from ../dist/ folder
+    const clientBundlePath = path.join(__dirname, "..", "dist", "index.html");
+
+    if (!existsSync(clientBundlePath)) {
+        if (process.env.NODE_ENV === "development") {
+            // In development, we just want to redirect to the Vite dev server
+            return res.redirect("http://localhost:5173");
+        } else {
+            // Looks like "npm run build:ui" wasn't run and the UI isn't built, show a nice error message instead
+            return res.status(404).send("Front-end not available.");
+        }
+    }
     res.sendFile(path.join(import.meta.dirname, "..", "dist", "index.html"));
 });