Three-legged dog

Three-legged dog is a metaphor for a crippled yet still functional technology infrastructure or application component. This anti-pattern can be applicable to a design or functional system. The expression may bring about a certain feeling of sorrow in imagining a cute fluffy dog limping along on three legs. Typically, an external entity or process has changed the original state of the design or functional system. It denotes the potential for instability to the point where any further subsequent changes may make the design or system unusable.

In terms of infrastructure or application design, the solution may have been based on industry best practices. Subsequent peer review processes, either to reduce cost or lack of understanding in the underlying components and concepts, have diminished the design to the point where so many concessions have been made that it may still be implemented and be functional however will resemble a three-legged dog.

In terms of functional systems, although they may have been coded or built around industry best practices subsequent changes have warped the original state to the point where the system now resembles a three-legged dog.