Express.js Deployment Basics

Once your Express.js application is ready, the next step is deployment - making the application accessible to users over the internet.

Deployment typically involves:

Running the application reliably
Managing environment variables
Handling process restarts
Configuring domains and HTTPS
Scaling the application

Obviously there are many deployment approaches but in this article covers two common ones: PM2 → Simple process management and Docker → Containerized deployments

Option 1: Deploying with PM2

PM2 is a production process manager for Node.js applications.

It provides:

Automatic restarts
Process monitoring
Background execution
Log management
Startup on server reboot

PM2 is one of the easiest ways to deploy Node.js applications on a VPS or cloud server.

Installing PM2

npm install -g pm2

Starting the Application

pm2 start app.js --name "my-api"

This runs the Express.js application in the background.

Enabling Auto-Start on Reboot

pm2 startup # Generates startup scripts
pm2 save # Saves the current PM2 process list

This ensures the application restarts automatically if the server reboots.

Useful PM2 commands

Command	Purpose
`pm2 list`	View running applications
`pm2 logs`	View application logs
`pm2 restart my-api`	Restart application
`pm2 stop my-api`	Stop application
`pm2 delete my-api`	Remove application

Option 2: Deploying with Docker

Docker packages applications into lightweight containers that run consistently across environments.

Docker helps solve the classic: “It works on my machine” problem by standardizing the runtime environment.

Containerization is widely used in modern backend infrastructure and cloud deployments.

Creating a Dockerfile

# Base image
FROM node:20-alpine

# Working directory inside container
WORKDIR /app

# Copies files into container
COPY package*.json ./

# Executes commands during build
RUN npm ci --only=production

COPY . .

# Documents application port
EXPOSE 3000

# Starts the application
CMD ["node", "app.js"]

Building the Docker Image

docker build -t my-api.

This creates a Docker image named: my-api.

Running the Container

docker run -d \ 
  -p 3000:3000 \
  --env-file .env \
  --name my-api \
  my-api

This:

Runs the container in detached mode
Maps port 3000
Loads environment variables
Names the container my-api

Other Key Considerations

Reverse Proxy & SSL: In production, Express.js applications are usually placed behind a reverse proxy such as Nginx for HTTPS, domain routing, load balancing, and traffic management.
Hosting Options: Express.js applications can be deployed on managed platforms like Render or Vercel, cloud providers such as AWS, or traditional VPS providers like Hetzner
Scaling & Architecture: As traffic grows, applications often scale horizontally by running multiple application instances behind a load balancer or container orchestration platform.
CI/CD pipelines: Automate testing, building, and deployment for faster iteration and reliability.
Monitoring & logging: Use tools like Prometheus, Grafana, or ELK stack to track performance and errors.

Deployment Basics for Express.js Applications