"Making systems resilient is fundamentally at odds with optimization, because optimizing a system means taking out any slack. A truly optimized, and thus efficient, system is only possible with near-perfect knowledge about the system, together with the ability to observe and implement a response. For a system to be reliable, on the other hand, there have to be some unused resources to draw on when the unexpected happens, which, well, happens predictably." (Deb Chachra, How Infrastructure Works, p. 209) Another way to look at this is that you cannot optimize for resilience. Resilience requires a kind of elasticity, an ability to stretch and reach but then to return, to spring back into a former shape—or perhaps to shapeshift into something new if the circumstances require it. Resilience is stretchy where optimization is brittle; resilience invites change where optimization demands continuity.
—Mandy Brown, from her post "Against Optimization" on A Working Library
