the two hard things

programming

'There are only two hard things in Computer Science: cache invalidation and naming things.'

The line is attributed to Netscape engineer Phil Karlton, and its endurance comes from being true: both problems are about keeping a name or a copy faithful to a changing reality. The community's favorite corollary adds a third: off-by-one errors. Quote it whenever a stale cache and a misleading variable name conspire in the same incident.

Also known as: cache invalidation and naming things

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