Continuous integration (CI) testing has evolved significantly over the decades, transitioning from manual, time-intensive processes to highly automated and rapid systems. Initially characterized by slow, manual code inspections in the 1980s, the advent of unit testing in the 1990s began to shift the landscape, although tests were still often slow and infrequent. The early 2000s saw the introduction of automated integration testing servers, such as Jenkins, which revolutionized testing by verifying each code change automatically. By the 2010s, cloud-based CI services like CircleCI and GitHub Actions became prevalent, offering zero-maintenance testing solutions and allowing even smaller teams to benefit from continuous testing. Modern CI practices focus on minimizing test times through parallelization, caching, and increasingly sophisticated build tools, while some organizations employ batching strategies to optimize resource use. Looking to the future, the potential integration of AI-assisted code reviews could further accelerate the process by identifying common coding errors faster than traditional methods, suggesting a return to fast, heuristic-based verification akin to earlier manual reviews but enhanced by advanced technology.