GoF (Gang of Four) design patterns used:

* [http://www.dofactory.com/Patterns/PatternSingleton.aspx Singleton], for forcing only one instance of {{Doctrine_Manager}}
* [http://www.dofactory.com/Patterns/PatternComposite.aspx Composite], for leveled configuration
* [http://www.dofactory.com/Patterns/PatternFactory.aspx Factory], for connection driver loading and many other things
* [http://www.dofactory.com/Patterns/PatternObserver.aspx Observer], for event listening
* [http://www.dofactory.com/Patterns/PatternFlyweight.aspx Flyweight], for efficient usage of validators
* [http://www.dofactory.com/Patterns/PatternFlyweight.aspx Iterator], for iterating through components (Tables, Connections, Records etc.)
* [http://www.dofactory.com/Patterns/PatternState.aspx State], for state-wise connections
* [http://www.dofactory.com/Patterns/PatternStrategy.aspx Strategy], for algorithm strategies

Enterprise application design patterns used:

* [http://www.martinfowler.com/eaaCatalog/activeRecord.html Active Record], Doctrine is an implementation of this pattern
* [http://www.martinfowler.com/eaaCatalog/unitOfWork.html UnitOfWork], for maintaining a list of objects affected in a transaction
* [http://www.martinfowler.com/eaaCatalog/identityField.html Identity Field], for maintaining the identity between record and database row
* [http://www.martinfowler.com/eaaCatalog/metadataMapping.html Metadata Mapping], for Doctrine DataDict
* [http://www.martinfowler.com/eaaCatalog/dependentMapping.html Dependent Mapping], for mapping in general, since all records extend {{Doctrine_Record}} which performs all mappings
* [http://www.martinfowler.com/eaaCatalog/foreignKeyMapping.html Foreign Key Mapping], for one-to-one, one-to-many and many-to-one relationships
* [http://www.martinfowler.com/eaaCatalog/associationTableMapping.html Association Table Mapping], for association table mapping (most commonly many-to-many relationships)
* [http://www.martinfowler.com/eaaCatalog/lazyLoad.html Lazy Load], for lazy loading of objects and object properties
* [http://www.martinfowler.com/eaaCatalog/queryObject.html Query Object], DQL API is actually an extension to the basic idea of Query Object pattern