What is CI/CD?
Continuous Integration (CI)
Continuous Integration means developers merge their code changes into a shared repository frequently, often several times a day. Each merge triggers an automated build and test run to catch integration issues early.
The goal is to avoid the painful 'integration hell' that happens when long-lived branches are merged. CI servers like Jenkins, GitLab CI, or GitHub Actions run the pipeline on every commit.
- Frequent merges to main branch
- Automated build and unit tests
- Fast feedback to developers
- Keeps codebase in a releasable state
Continuous Delivery vs Deployment
Continuous Delivery extends CI by automatically deploying every change to a staging or pre-production environment. The software is always ready for a production release, but a human decides when to push the button.
Continuous Deployment goes one step further: every change that passes all tests is automatically deployed to production. This requires high confidence in your test suite and monitoring.
- Delivery: manual approval for production
- Deployment: fully automated to production
- Both rely on robust automated testing
- Deployment requires strong observability
Why It Matters
CI/CD reduces the risk of releases by making them small and frequent. It also shortens the feedback loop, so bugs are found and fixed faster.
For DevOps teams, CI/CD is a core practice that enables rapid iteration and reliable software delivery.
Common mistakes
- Thinking CI/CD is just a tool—it's a cultural and process change first.
- Assuming CI automatically means CD; they are separate stages.
- Believing that CI/CD eliminates the need for manual testing or QA.
