I think greater compartmentalization of software is long overdue.<p>For a program like this, there ought to be a Sacred Core that Does Very Little and has implementations of key protocols that can’t be touched without the blessing of about 5 senior engineers and the personal seal of the CEO or some such.<p>In other words, it should be <i>unbelievably</i> hard to screw with parts of the program that are crucial, while making changes that shouldn’t have anything to do with it.  (Heck, for all we know, they were adding Windows 10 Tiles™ when this screw-up occurred.)