diff --git a/backend/server/dockerfile b/backend/server/dockerfile
index 645f4d4..08b22ea 100644
--- a/backend/server/dockerfile
+++ b/backend/server/dockerfile
@@ -2,8 +2,8 @@ FROM node:20
 
 # Security: Drop all capabilities
 USER root
-RUN apt-get update && apt-get install -y libcap2-bin
-RUN setcap cap_net_bind_service=+ep /usr/local/bin/node
+RUN apt-get update && apt-get install -y libcap2-bin && \
+  setcap cap_net_bind_service=+ep /usr/local/bin/node
 
 WORKDIR /code
 
@@ -15,14 +15,19 @@ COPY . .
 
 RUN npm run build
 
-# Security: Create non-root user and assign ownership
-RUN useradd -m myuser
-RUN mkdir projects && chown -R myuser:myuser projects
-USER myuser
+RUN useradd -m sboxuser
+RUN mkdir projects && chown -R sboxuser:sboxuser projects
 
-# user namespace mapping
+# todo user namespace mapping
 
-EXPOSE 3000
+RUN apt-get install -y firejail
+
+RUN echo '#!/bin/bash\nexec firejail --private=/projects --noprofile node dist/index.js' > /start.sh
+RUN chmod +x /start.sh
+
+USER sboxuser
+
+EXPOSE 8000
 EXPOSE 4000
 
-CMD [ "node", "dist/index.js" ]
\ No newline at end of file
+CMD ["/start.sh"]
diff --git a/backend/server/src/index.ts b/backend/server/src/index.ts
index c4195d3..b7ecd43 100644
--- a/backend/server/src/index.ts
+++ b/backend/server/src/index.ts
@@ -342,8 +342,8 @@ io.on("connection", async (socket) => {
 
     const onExit = pty.onExit((code) => console.log("exit :(", code));
 
+    pty.write("export PS1='\\u > '\r");
     pty.write("clear\r");
-    pty.write("export PS1='> '\r");
 
     terminals[id] = {
       terminal: pty,
diff --git a/backend/storage/src/startercode.ts b/backend/storage/src/startercode.ts
index a277023..495bbfb 100644
--- a/backend/storage/src/startercode.ts
+++ b/backend/storage/src/startercode.ts
@@ -56,7 +56,7 @@ import react from '@vitejs/plugin-react'
 export default defineConfig({
   plugins: [react()],
   server: {
-    port: 3000,
+    port: 8000,
   },
 })
 `,
diff --git a/frontend/components/editor/preview/index.tsx b/frontend/components/editor/preview/index.tsx
index 34fbca7..7eb6f49 100644
--- a/frontend/components/editor/preview/index.tsx
+++ b/frontend/components/editor/preview/index.tsx
@@ -34,7 +34,7 @@ export default function PreviewWindow({
           <div className="text-xs">
             Preview
             <span className="inline-block ml-2 items-center font-mono text-muted-foreground">
-              localhost:3000
+              localhost:8000
             </span>
           </div>
           <div className="flex space-x-1 translate-x-1">
@@ -51,7 +51,7 @@ export default function PreviewWindow({
 
                 <PreviewButton
                   onClick={() => {
-                    navigator.clipboard.writeText(`http://${ip}:3000`);
+                    navigator.clipboard.writeText(`http://${ip}:8000`);
                     toast.info("Copied preview link to clipboard");
                   }}
                 >
@@ -77,7 +77,7 @@ export default function PreviewWindow({
             ref={ref}
             width={"100%"}
             height={"100%"}
-            src={`http://${ip}:3000`}
+            src={`http://${ip}:8000`}
           />
         </div>
       )}