What Is CI/CD?
Continuous Integration and Continuous Delivery
CI/CD automates the process of testing and deploying code. Continuous Integration (CI) automatically builds and tests code on every commit. Continuous Delivery (CD) automatically deploys tested code to staging or production environments.
How CI/CD Works
A typical CI/CD pipeline: developer pushes code → CI runs linting, tests, and builds → if all pass, CD deploys to staging → after approval or automatically, CD deploys to production. Tools: GitHub Actions, GitLab CI, CircleCI, Jenkins.
CI catches bugs early by running your test suite on every push. CD eliminates manual deployment steps. Together, they let teams deploy multiple times per day with confidence instead of dreading monthly releases.
Why Developers Use CI/CD
Every professional software team uses CI/CD. It catches bugs before they reach production, ensures consistent builds, and enables rapid iteration. Without CI/CD, deployments are manual, error-prone, and stressful.
Key Concepts
- Pipeline — A series of automated steps (build, test, deploy) triggered by code changes
- Build Step — Compiling code, installing dependencies, and creating deployable artifacts
- Test Step — Running unit tests, integration tests, and linting automatically
- Deploy Step — Pushing tested code to staging or production environments
Frequently Asked Questions
What CI/CD tool should I use?
GitHub Actions if your code is on GitHub — it's free for public repos and well-integrated. GitLab CI for GitLab users. Jenkins for complex enterprise setups. CircleCI and Buildkite for high-performance needs.
How is CI different from CD?
CI is about testing (build and test every commit). CD is about deploying (automatically ship tested code). CI without CD means you test automatically but deploy manually. Full CI/CD automates both.