At an F8 keynote, many years ago, Zuck admitted on stage that when you "move fast and break things" all the time, well, everything is constantly broken (duh) an

At an F8 keynote, many years ago, Zuck admitted on stage that when you "move fast and break things" all the time, well, everything is constantly broken (duh) and it made it so hard for even their own engineers to maintain their own applications (which exist on a very large number of platforms) that he appreciated it must have been impossible for third parties to use their developer platform, and so he formally changed the motto to "move fast with stable infra".