Sensenmann: Code Deletion at Scale
The most difficult part about code deletion is practicing the Chesterton's Fence principle:> In the matter of reforming things, as distinct from deforming them, there is one plain and simple principle; a principle which will probably be called a paradox. There exists in such a case a certain institution or law; let us say, for the sake of simplicity, a fence or gate erected across a road. The more modern type of reformer goes gaily up to it and says, “I don’t see the use of this; let us clear it away.” To which the more intelligent type of reformer will do well to answer: “If you don’t see the use of it, I certainly won’t let you clear it away. Go away and think. Then, when you can come back and tell me that you do see the use of it, I may allow you to destroy it.https://wiki.lesswrong.com/wiki/Chesterton%27s_FenceWhile this tool certainly does the job of proposing code deletions, that's the easier part.  The harder part is knowing why the code exists in the first place, which is necessary to know whether it's truly a good idea to remove it.  Google, smartly, is leaving that part up to a human (for now).