Node.js Backend Deployment on AWS EC2

✅ STAR Methodology Answer:

S - Situation

During my cloud learning journey, I wanted to gain hands-on experience in deploying backend services on cloud infrastructure. I chose to work with a Node.js application and deploy it on AWS EC2, simulating a real-world production backend deployment scenario.

T - Task

My goal was to:

• Deploy a simple Node.js backend (REST API).

• Host it on an EC2 instance.

• Configure networking for external access.

• Ensure high availability and proper security.

• Test API endpoints using Postman. This project was aimed at understanding the end-to-end flow of cloud-based deployments and managing backend infrastructure.

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A - Action (Detailed Step-by-Step)

1. Setup the EC2 Instance

• Launched an EC2 instance (Amazon Linux 2) via AWS Console.

• Chose a t2.micro instance under the Free Tier, and selected the correct VPC and subnet.

• Created a key pair (.pem) for SSH access.

• Opened port 22 for SSH, and port 3000 (or 80/443) for Node.js app in the Security Group.

2. SSH into EC2 & Setup Environment

• Connected to EC2 using:

    bashCopyEditssh -i "my-key.pem" ec2-user@<Public-IP>
  

• Installed Node.js and npm:

    bashCopyEditsudo yum update -y
    curl -sL https://rpm.nodesource.com/setup_18.x | sudo bash -
    sudo yum install -y nodejs
  

3. Upload Node.js Project to EC2

• Used Git to clone the repository or SCP to transfer files from local to EC2.

    bashCopyEditscp -i "my-key.pem" -r ./my-node-app ec2-user@<Public-IP>:/home/ec2-user
  

4. Install Dependencies & Start the Server

• Navigated to the project folder:

    bashCopyEditcd my-node-app
    npm install
  

• Started the server:

    bashCopyEditnode index.js
  

5. Configure the App to Run in Background (PM2 or nohup)

• Installed PM2:

    bashCopyEditnpm install -g pm2
    pm2 start index.js
    pm2 startup
    pm2 save
  

6. Security Group & Firewall Configuration

• Ensured inbound rules allowed traffic to port 3000 or 80.

• Verified iptables or firewalld settings (if needed).

7. Tested API with Postman

• Verified public IP and tested API routes from Postman.

• Confirmed response status codes and payloads.

8. Optional: Custom Domain + Reverse Proxy (Advanced)

• (Optional) Set up Nginx as a reverse proxy for production-ready setup.

• Linked to a custom domain using Route 53 (optional learning addition).

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R - Result

• Successfully deployed a Node.js backend on AWS EC2 with public accessibility.

• Gained strong understanding of:

  • Cloud networking

  • SSH & Linux setup

  • Security groups and firewall rules

  • Backend deployment lifecycle

• Validated API functionality using Postman.

• Improved confidence in handling real-world backend deployments on cloud.

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👨‍💼 How to Explain in Interview

“I worked on deploying a Node.js backend on AWS EC2 to simulate real-world cloud deployments. I launched and configured the EC2 instance, installed the runtime environment, transferred code, ran the server with PM2, and configured security groups for accessibility. I also tested the endpoints using Postman to ensure proper request/response handling. This gave me hands-on understanding of backend cloud deployments and taught me about cloud infrastructure, networking, and server configuration.”

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💬 10 Follow-Up Questions the Interviewer Might Ask

✅ 5 Challenges Faced & How I Overcame Them

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1. SSH Connection Error to EC2

🔸Challenge:
When I first launched the EC2 instance, I was unable to SSH into it. The terminal kept saying "Permission denied" or "Timed out".

🔧 Solution:

• Ensured that the Security Group had port 22 open for inbound SSH access.

• Verified I was using the correct public IP and .pem key file.

• Changed the permissions of the key with:

    bashCopyEditchmod 400 my-key.pem
  

• Used the right user (ec2-user) in the SSH command.

💡 Learning: Importance of network rules and secure SSH practices.

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2. Node.js Not Recognized / Installation Issues

🔸Challenge:
After SSHing into the instance, the node and npm commands were not recognized.

🔧 Solution:

• Learned that Amazon Linux 2 does not come with Node.js pre-installed.

• Installed it manually using Nodesource:

    bashCopyEditcurl -sL https://rpm.nodesource.com/setup_18.x | sudo bash -
    sudo yum install -y nodejs
  

💡 Learning: Gained hands-on experience with package installation and dependency management on Linux.

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3. Application Stopped After Logout

🔸Challenge:
The Node.js app would shut down whenever I closed the SSH terminal session.

🔧 Solution:

• Installed PM2 for better process management and persistence after reboot:

    bashCopyEditpm2 start index.js
    pm2 save
    pm2 startup
  

💡 Learning: Understood the importance of background process managers like PM2 in real-world deployments.

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4. API Not Accessible Publicly

🔸Challenge:
Though the server was running on port 3000, I couldn’t access it from my browser or Postman using the public IP.

🔧 Solution:

• Realized that I needed to add an inbound rule in the Security Group for port 3000.

• Added rule:

  • Type: Custom TCP

  • Port: 3000

  • Source: 0.0.0.0/0 (for testing)

• Restarted the app and tested successfully.

💡 Learning: Learned about AWS networking and security best practices using security groups and firewalls.

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5. Application Not Auto-Starting After EC2 Reboot

🔸Challenge:
Every time I restarted the EC2 instance, the Node.js app wouldn’t start automatically.

🔧 Solution:

• Configured PM2 to generate a startup script:

    bashCopyEditpm2 startup
    pm2 save
  

• This ensured that PM2 would auto-launch all apps on reboot.

💡 Learning: Learned about service persistence and automation in Linux-based systems.