Continuous Integration (CI)
Continuous integration is the practice of frequently merging code into a shared repository, with each change automatically built and tested to surface defects early.
Continuous integration (CI) is a software development practice in which developers integrate their work into a shared mainline many times a day. Each integration triggers an automated build and test run, giving fast feedback on whether the change is safe.
How It Works
Developers commit small changes to a version control system. A CI server watches the repository and, on each push, checks out the code, compiles it, and runs the automated test suite. Static analysis, linting, and security scans often run in the same stage. If any step fails, the team is notified and the offending change is fixed before more work piles on top of it. Short-lived branches and trunk-based development keep merges small and conflicts rare.
Why It Matters
Without CI, integration is deferred until late in a project, when many divergent changes collide at once. This "integration hell" is expensive and unpredictable. CI replaces it with a steady stream of verified, mergeable changes. A green build becomes a shared signal of health, and defects surface within minutes rather than weeks. CI is the foundation on which continuous delivery and deployment are built; you cannot reliably release software you have not continuously verified.
Related Terms
CI is the first stage of a delivery pipeline and pairs naturally with continuous delivery and continuous deployment. It depends heavily on automation and on a disciplined version control workflow.