Online appendix for paper "Continuous Code Quality: Are We (Really) Doing That?" by Carmine Vassallo, Fabio Palomba, Alberto Bacchelli, Harald C. Gall. The paper will appear in the proceedings of the 33rd IEEE/ACM International Conference on Automated Software Engineering (ASE), Montpellier, France, 2018. Abstract. Continuous Integration (CI) is a software engineering practice where developers constantly integrate their changes to a project through an automated build process. The goal of CI is to provide developers with prompt feedback on several quality dimensions after each change. Indeed, previous studies provided empirical evidence on a positive association between properly following CI principles and source code quality. A core princi...