ContinuousIntegration

Continuous integration is a software development practice where members of a team integrate their work frequently, usually multiple times per day, into a shared repository. Each integration is verified by an automated build and a set of tests to detect integration errors as early as possible.

A continuous integration system monitors the repository for changes, runs a pipeline that may include compilation, unit tests, integration tests, static analysis, and packaging, and provides rapid feedback to developers through dashboards and alerts.

Origin and usage: CI arose with practices from Extreme Programming in the late 1990s and early 2000s and has become a core element of modern software delivery. It is often implemented as part of a broader CI/CD pipeline, using tools such as Jenkins, GitHub Actions, GitLab CI, CircleCI, or Travis CI.

Benefits and challenges: Benefits include early defect detection, reduced integration risk, more frequent releases, consistent build environments, and improved collaboration. Typical challenges include flaky tests, long-running builds, brittle pipelines, and maintaining test coverage and environment parity.

Relation to CD: Continuous integration focuses on merging code and validating builds; continuous delivery and continuous deployment extend that process to automatic release and deployment to production, subject to gating criteria.