In Africa the saying goes
Kill Bill, Elle Driver: [reading] In Africa, the saying goes ‘In the bush, an elephant can kill you, a leopard can kill you, and a black mamba can kill you. But only with the mamba is death sure.’ Hence its handle, ‘Death Incarnate.'” Pretty cool, huh?
Now in software development jungle one of three things can kill you: unexpected growth of traffic, unexpected growth of data or incompetent changes. But only with incompetent changes the death is sure because the same people who broke the performance are unlikely to be the same people finding the proper optimisation to fix it ;-)