In Yandex, uploading all working code to servers is controlled by the Debian package system.
Here is what one of Yandex programmers, Ivan Sagalaev, writes: softwaremaniacs.org/blog/2007/08/15/deb-packages-in-yandex/#more-269 Upon closer inspection, it turned out that apt is a powerful and versatile thing that has everything you need for such a scenario. Admins do not need to delve into the details of each project: the developer simply sends the name of the package that needs to be installed, and it is put. Verification of versions, installation of dependencies, pre-setting, prescribing init-scripts - all this can be described in the package. And I remember that the installation process of one of its services was described in detail with words in the wiki, so that the admin did all this manually :-). And if in the working code there are suddenly wild bugs that were not revealed by internal testing, then the admin, without knowing anything about the code, can simply replace it with the previous working version.