continuous-integration
Continuous Integration (CI) is a software development practice where developers frequently merge code changes into a central repository, after which automated builds and tests are run.
Continuous Integration (CI) is a software development practice where developers regularly merge their code changes into a central repository, typically multiple times a day. Each merge is then verified by an automated build and an automated test suite. The primary goal of CI is to detect integration errors as quickly as possible, preventing code conflicts and ensuring that the codebase remains in a consistently working state. When a developer commits code, an automated system (like Jenkins, GitLab CI, or GitHub Actions) detects the change, pulls the latest code, compiles it (builds it), and runs a series of tests (e.g., unit tests, basic integration tests). If the build or any tests fail, the team is immediately notified, and the faulty code is typically fixed before proceeding. This practice significantly reduces integration problems that often arise in traditional development cycles where code is merged infrequently. By catching issues early, CI leads to higher quality code, faster development cycles, and improved team collaboration, forming the foundation for Continuous Delivery and Continuous Deployment.
graph LR
Center["continuous-integration"]:::main
Pre_logic["logic"]:::pre --> Center
click Pre_logic "/terms/logic"
Rel_cicd["cicd"]:::related -.-> Center
click Rel_cicd "/terms/cicd"
Rel_continuous_delivery["continuous-delivery"]:::related -.-> Center
click Rel_continuous_delivery "/terms/continuous-delivery"
Rel_cicd_pipeline["cicd-pipeline"]:::related -.-> Center
click Rel_cicd_pipeline "/terms/cicd-pipeline"
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🧠 Knowledge Check
🧒 Explain Like I'm 5
It's like everyone in [class](/en/terms/class) doing a small part of a big drawing and checking with each other constantly so the whole picture looks good.
🤓 Expert Deep Dive
Continuous Integration is a foundational practice in modern software development, particularly within Agile and DevOps methodologies. It fundamentally shifts the integration point from infrequent, large-scale merges to frequent, small-scale integrations. The core mechanics involve a version control system (e.g., Git), an automated build system, and an automated testing framework. The build system compiles source code into executable artifacts, while the test suite verifies the functionality and correctness of the code. The frequency of integration is key; integrating multiple times per day minimizes the scope of changes between integrations, making it easier to pinpoint the source of build or test failures. Architecturally, CI pipelines are often implemented using dedicated CI servers or cloud-based services. The effectiveness of CI is directly proportional to the speed and reliability of the build and test suite. Slow or flaky tests undermine the practice. Trade-offs include the initial investment in setting up robust automation and the discipline required from the development team to integrate frequently. Failure to do so can lead to "integration hell."