I asked ChatGPT for "CI/CD - the what, why how" :-)

This is what I got:

What is CI/CD?

CI/CD is a way of building and releasing software that makes change small, frequent, and safe instead of big, rare, and terrifying.

It stands for:

• Continuous Integration (CI) – regularly merging code into a shared codebase and automatically testing it.
• Continuous Delivery / Deployment (CD) – automatically preparing (or releasing) that code to users.

In plain English:

Every small change you make gets automatically checked and (optionally) shipped.

No drama. No “integration week”. No release weekend pizza marathons.

Why do we need it?

Because humans are terrible at:

• Remembering to run all the tests
• Integrating huge batches of changes at once
• Releasing without breaking something

Without CI/CD, teams tend to:

• Merge code infrequently
• Fear deployments
• Break things late in the process
• Argue about whose change caused the bug

With CI/CD, you:

• Catch problems minutes after writing code
• Reduce risk by releasing in small increments
• Build confidence in your system
• Remove manual, error-prone deployment steps

It turns software delivery from a stressful event into a boring routine.

And in engineering, boring is good.

How does it actually work?

Here’s the typical flow:

1. You push code

You commit your changes to a shared repository (e.g. GitHub).

2. CI starts automatically

A pipeline runs:

• Install dependencies
• Build the app
• Run tests
• Check formatting/linting
• Possibly run security scans

If anything fails → you fix it immediately.

3. CD prepares or performs deployment

If CI passes:

• Continuous Delivery: The system creates a deployable build, ready to release at the push of a button.
• Continuous Deployment: It automatically ships to production.

No FTP.
No copying files manually.
No “did you remember the config?”.

It’s scripted and repeatable.

What changes culturally?

CI/CD isn’t just tooling. It changes behaviour:

• Smaller pull requests
• Faster feedback loops
• Less fear of deployment
• Treating production like a normal environment, not a sacred ceremony

It moves you from:

“Let’s hope this release works”

to

“We deploy 15 times a day. Of course it works.”

A Simple Mental Model

Think of CI/CD like airport security.

Every bag (code change) goes through:

• Automated scanning (tests)
• Rule enforcement (linters/checks)
• Packaging (build)
• Boarding (deploy)

You don’t inspect everything manually.
You trust the system because it runs every single time.