The Titanic effect: The severity with which a system fails is directly proportional to the intensity of the designer’s belief that it cannot fail. – R.A. De Millo, R.J. Lipton, and A.J. Perlis, “Social processes and proofs of theorems and programs,” Communications of the ACM, 1979

## Universal technique

cout

A program is a human artifact; a real-life program is a complex human artifact; and any human artifact of sufficient size and complexity is imperfect. – (op. cit.)

## Xcode specific techniques

Programs are jagged and full of holes and caverns. Every programmer knows that altering a line or sometimes even a bit can utterly destroy a program or mutilate it in ways that we do not understand and cannot predict. And yet at other times fairly substantial changes seem to alter nothing; the folklore is filled with stories of pranks and acts of vandalism that frustrated the perpetrators by remaining forever undetected. – (op. cit.)

## Linux specific techniques

There is a classic science-fiction story about a time traveler who goes back to the primeval jungles to watch dinosaurs and then returns to find his own time altered almost beyond recognition. Politics, architecture, language–even the plants and animals seem wrong, distorted. Only when he removes his time-travel suit does he understand what has happened. On the heel of his boot, carried away from the past and therefore unable to perform its function in the evolution of the world, is crushed the wing of a butterfly. Every programmer knows the sensation: A trivial, minute change wreaks havoc in a massive system. Until we know more about programming, we had better for all practical purposes think of systems as composed, not of sturdy structures like algorithms and smaller programs, but of butterflies’ wings. – (op. cit.)