PM2

This lesson covers PM2. Let us learn this step by step — no rush, no jargon first.

What you will learn

• What pm2 means — in normal words, not textbook words
• How it works step by step
• Code you can run today on your laptop
• Where teams use this in real projects

Before you start

• Software: Node.js LTS from nodejs.org, VS Code, and a terminal
• Knowledge: Earlier lessons in this Node.js course
• Previous lesson: Kubernetes — Complete Guide

Explain it simply

PM2 keeps your Node app running — restarts on crash, cluster mode, and simple deploys on a VPS.

Why developers use this

• Shipping is a core skill
• Automate tests and deploy
• Portfolio needs a live URL

How it works (step by step)

1. Tests pass on your machine.
2. Build a Docker image or set Node version on the host.
3. Set environment variables on the server (never commit secrets).
4. Hit the health URL and watch logs for the first real users.

Code example — type this yourself

pm2 start server.js --name api
pm2 logs api
pm2 restart api

npm install -g pm2. Good stepping stone before Kubernetes.

What each part does

• pm2 start server.js --name api — Line 1: runs as written.
• pm2 logs api — Line 2: runs as written.
• pm2 restart api — Line 3: runs as written.

Real life: where PM2 shows up

After tests pass locally, the team uses PM2 to ship the same build to staging, then production, with the same Node version everywhere. In interviews, explain the trade-off you chose and what you would measure in production.

Try it yourself — hands-on

1. Create a new file (e.g. pm2-demo.js) in an empty folder
2. Type the example code for PM2 yourself — typing helps memory
3. Run node on that file and read the output
4. Change one line (a value, a message, a route path) and run again to see what breaks or improves

Common mistakes (avoid these)

• Skipping the terminal — PM2 only feels easy after you run code yourself.

Interview note

Senior interviews may ask how PM2 behaves under load, failure, or security review — mention logging, timeouts, and validation.

Summary

• You can explain PM2 in your own words
• You ran working code — not just read about it
• You know one mistake to avoid and one real place teams use this