Deploy Next.js 15 & Express Backend to cPanel: A Battle-Tested Guide

What I learned from a frustrating but educational deployment journey

Deploying modern JavaScript frameworks to traditional cPanel hosting can feel like fitting a square peg into a round hole. After hours of debugging EAGAIN errors, CORS issues, and resource limits, I finally got my Next.js 15 frontend and Express.js backend running smoothly on Jagoan Hosting's cPanel. Here's everything I learned.

The Stack

• Frontend: Next.js 15, React 19, Material-UI v7
• Backend: Express.js, TypeScript, Sequelize
• Hosting: Jagoan Hosting Cloud NextGen (cPanel with Node.js support)
• Domains:
  • Frontend: dapurenakeeco.com
  • Backend API: api.dapurenakeeco.com

---

Part 1: Deploying the Express Backend

The backend was relatively straightforward. Here's the process:

Step 1: Build Locally

cd restaurant-backend
npm run build

This compiles TypeScript to JavaScript in the dist/ folder.

Step 2: Prepare Files for Upload

Create a zip containing:

• dist/ (compiled code)
• package.json
• package-lock.json
• .env (with production values)

DO NOT include node_modules - we'll install on the server.

Step 3: Setup Node.js App in cPanel

1. Go to cPanel → Setup Node.js App
2. Click Create Application
3. Configure:
   • Node.js Version: 20.x
   • Application Mode: Production
   • Application Root: restaurant-backend
   • Application URL: api.dapurenakeeco.com
   • Startup File: dist/app.js

Step 4: Upload & Install

1. Upload your zip to the restaurant-backend folder
2. Extract it
3. Click Run NPM Install in the Node.js App interface
4. Click Start App

CORS Configuration (Critical!)

Make sure your backend allows requests from your frontend domain:

// app.ts
app.use(
  cors({
    origin: [
      "https://dapurenakeeco.com",
      "http://dapurenakeeco.com",
      "http://localhost:3000",
    ],
    credentials: true,
    methods: ["GET", "POST", "PUT", "DELETE", "OPTIONS"],
  }),
);

Pro tip: Double-check your domain spelling! I wasted time because of a typo (dapurenakeco vs dapurenakeeco).

---

Part 2: Deploying Next.js 15 (The Hard Part)

This is where things got interesting. Modern Next.js is resource-hungry, and shared hosting has strict limits.

The Problem: EAGAIN Errors

When I tried npm install on the server, I got:

Error: spawn npm EAGAIN
errno: -11
code: 'EAGAIN'
syscall: 'spawn npm'

Translation: The server hit its process limit (nProc). Shared hosting typically limits you to 20-50 concurrent processes, and npm install for a Next.js project spawns way more than that.

The Solution: Custom Server + Local Dependencies

After many failed attempts, I found a working approach from Jagoan Hosting's own tutorial.

Step 1: Create a Custom Server

Create server.js in your project root:

const { createServer } = require("http");
const { parse } = require("url");
const next = require("next");

const dev = process.env.NODE_ENV !== "production";
const hostname = "localhost";
const port = process.env.PORT || 8080;

const app = next({ dev, hostname, port });
const handle = app.getRequestHandler();

app.prepare().then(() => {
  createServer(async (req, res) => {
    try {
      const parsedUrl = parse(req.url, true);
      await handle(req, res, parsedUrl);
    } catch (err) {
      console.error("Error occurred handling", req.url, err);
      res.statusCode = 500;
      res.end("internal server error");
    }
  }).listen(port, (err) => {
    if (err) throw err;
    console.log(`> Ready on http://${hostname}:${port}`);
  });
});

Step 2: Update package.json

{
  "scripts": {
    "start": "NODE_ENV=production node server.js",
    "build": "next build"
  }
}

Step 3: Optimize for Shared Hosting

Add this to next.config.js to prevent resource exhaustion:

const nextConfig = {
  experimental: {
    workerThreads: false,
    cpus: 1,
  },
};

Step 4: Build Locally

npm run build

Step 5: Prepare Upload Package

Zip these files/folders:

• .next/ (build output)
• pages/
• public/
• src/
• server.js
• package.json
• package-lock.json
• next.config.js
• tsconfig.json
• .env.local

DO NOT include node_modules - we'll run npm install on the server.

---

Step 6: Upload & Configure in cPanel

This is the most critical part. Follow these steps carefully.

6.1 Create the Node.js Application

1. Log in to cPanel
2. Go to Setup Node.js App
3. Click Create Application
4. Fill in the settings:

Setting	Value
Node.js Version	20.x (or latest LTS)
Application Mode	Production
Application Root	e-menu-fe (your folder name)
Application URL	dapurenakeeco.com (your domain)
Application Startup File	server.js

5. Click Create

6.2 Upload Your Files

1. Go to File Manager in cPanel
2. Navigate to e-menu-fe folder
3. Delete any default files (like app.js)
4. Click Upload and select your zip file
5. After upload, right-click the zip → Extract
6. Verify your folder structure looks like:

e-menu-fe/
├── .next/
├── pages/
├── public/
├── src/
├── server.js
├── package.json
├── package-lock.json
├── next.config.js
└── tsconfig.json

6.3 Set Environment Variables

1. Go back to Setup Node.js App
2. Click the pencil icon (Edit) on your app
3. Scroll to Environment Variables
4. Click Add Variable and add:

Name	Value
PORT	8080
NEXT_PUBLIC_API_URL	https://api.dapurenakeeco.com

5. Click Save

6.4 Start the Application

1. In Setup Node.js App, find your app
2. Click Run NPM Install and wait for it to complete
3. Click Start App (or Restart if already running)
4. Wait 10-30 seconds for Next.js to initialize
5. Visit your domain to verify it's working

---

Common Issues & Solutions

Issue: "Couldn't find any pages or app directory"

Cause: Missing source files on server.

Fix: Make sure you uploaded pages/, src/, and tsconfig.json.

Issue: "ENOENT: no such file... required-server-files.json"

Cause: Incomplete .next folder.

Fix: Rebuild locally with npm run build and re-upload the entire .next folder.

Issue: "fork: Resource temporarily unavailable"

Cause: Too many processes running. Your account is locked.

Fix: Contact hosting support to kill stuck processes, or wait a few hours. Then upload with node_modules included to avoid server-side installs.

Issue: CORS errors

Cause: Backend doesn't allow frontend origin.

Fix:

1. Check domain spelling in CORS config
2. Ensure both HTTP and HTTPS variants are listed
3. Rebuild and re-upload backend

Issue: Non-standard NODE_ENV warning

Cause: cPanel sets a weird NODE_ENV value.

Fix: Set NODE_ENV=production explicitly in your start script (already done in our package.json).

---

Key Takeaways

1. Shared hosting has limits - Be aware of resource limits, but modern plans can handle npm install.

2. Use custom server.js - The default Next.js startup doesn't play well with cPanel.

3. cpus: 1 saves lives - Limit worker threads to avoid hitting process limits.

4. Double-check your domains - Typos in CORS configs cause silent failures.

---

Final Thoughts

Would I recommend cPanel for Next.js 15? Honestly, for small projects with limited traffic, it works. But if you're building something serious, consider:

• Vercel (made for Next.js)
• Railway/Render (easy Node.js deployment)
• VPS with Docker (full control)