continuous integration

 Continuous Integration  is the act of continuously building and testing developer changes using automation such that mistakes and bugs are discovered closer to the point where the code was changed.

It's often done in conjunction with automated testing of the build artifacts and, if everything passes, then is deployed using continuous deploy methods.

Software
Software often used for continuous integration:
 * Jenkins

Services
Services often used for continuous integration:
 * CircleCI
 * TravisCI