In software engineering, an anti-pattern (or antipattern) is a design pattern that appears obvious but is ineffective or far from optimal in practice.
The term was coined in 1995 by Andrew Koenig, inspired by Gang of Four's book Design Patterns, which developed the concept of design patterns in the software field. The term was widely popularized three years later by the book AntiPatterns, which extended the use of the term beyond the field of software design and into general social interaction. According to the authors of the latter, there must be at least two key elements present to formally distinguish an actual anti-pattern from a simple bad habit, bad practice, or bad idea:
* Some repeated pattern of action, process or structure that initially appears to be beneficial, but ultimately produces more bad consequences than beneficial results, and
* A refactored solution that is clearly documented, proven in actual practice and repeatable.
Often pejoratively named with clever oxymoronic neologisms, many anti-pattern ideas amount to little more than mistakes, rants, unsolvable problems, or bad practices to be avoided if possible. Sometimes called pitfalls or dark patterns, this informal use of the term has come to refer to classes of commonly reinvented bad solutions to problems. Thus, many candidate anti-patterns under debate would not be formally considered anti-patterns.
By formally describing repeated mistakes, one can recognize the forces that lead to their repetition and learn how others have refactored themselves out of these broken patterns.