How the TYPO3 project ensures code quality through peer-reviews using "Gerrit Code Review" "Gerrit Code Review" is an open-source software and acts as a gatekeeper in front of the Git repositories. Gerrit ensures submitted code to be approved by multiple persons and optionally also Continuous Integration systems. Gerrit has been developed by Google for Android development. It is used by several companies and open-source projects, including Eclipse, OpenStack, and TYPO3. This talk presents Gerrit itself and the workflow and lessons learned in a big, community-driven open-source project: the TYPO3 project. Gerrit is used here for all top-level projects (TYPO3 CMS, TYPO3 Flow, TYPO3 Neos) since two years to handle every single code change. In addition to human reviews, automatic tests in Jenkins and TravisCI are executed. Gerrit brings transparency into our community-driven project and allows everybody to participate by pushing patches and voting for/against any change.