Continuous Integration
Continuous Integration (CI) is the practice of merging code changes into a shared codebase frequently — multiple times a day — with each merge automatically built and tested, catching integration problems within minutes of them being introduced rather than days or weeks later.
Before CI became standard practice, teams often integrated code infrequently — "integration hell" was the well-earned nickname for the painful process of merging weeks of divergent work all at once, discovering conflicts and incompatibilities in a single overwhelming batch instead of small, manageable increments.
CI's core promise is that automated tests run on every single change, so a broken build or a regression is caught and attributed to a specific, small commit almost immediately — dramatically easier to diagnose and fix than a failure discovered days later, buried among dozens of unrelated intervening changes.
