Applying simple interfaces to intricate algorithms

• Unifying interfaces from subsystems for ease of use and reusability
• Implementing the Facade pattern

Varying functionality by programming to interfaces

• Creating abstractions to enhance application adaptability and flexibility
• Exploiting the Strategy pattern

Extending object behavior dynamically

• Increasing functionality without impacting existing code
• Composing objects with the Decorator pattern

Achieving reuse and flexibility

• Eliminating code duplication by outlining an algorithm
• Employing the Template Method pattern

Interfacing incompatible classes

• Transforming an interface to add value to existing code
• Harnessing the Adapter pattern

Automating unit testing

• Shortening development cycles with automated tests
• Eliminating regression errors with reusable tests

Integrating testing and coding

• Applying the test–first programming practice
• Generating immediate red–green feedback for increased code quality and shortened feature development cycles
• Organizing, coordinating and running test cases
• Isolating a class test environment with the Mock–Object pattern for reliable and repeatable testing
• Tracking the Red–Green–Refactor rhythm for feedback

Refactoring code to improve design

• Improving design with behavior preserving refactorings
• Eliminating code duplication by refactoring to patterns

Designing the application architecture

• Layering architectures for reusability, durability and scalability
• Decoupling object creation with the Factory pattern
• Preserving object identity with the Identity Map pattern

Programming application tiers

• Isolating UI layers with the MVC and MVVM patterns
• Organizing state–rich applications with the State pattern
• Restructuring database tables without impacting code

Modeling a business area

• Liberating rich Business Object Models from database structures using the Domain Model pattern
• Mapping rich Business Objects to database tables with the Data Mapper pattern
• Collapsing Business Object hierarchies with the Inheritance Mapper pattern
• Exploiting declarative programming in Microsoft Entity Framework to implement Data Mapping classes

Organizing and implementing business logic

• Managing Persistence Ignorant Entity types with Entity Framework
• Manipulating groups of Entities with business logic classes

Applying S.O.L.I.D. principles of class design

• Single Responsibility
• Open–Closed
• Liskov Substitution
• Interface Segregation
• Dependency Inversion

Easing data access code

• Reducing database access code by exploiting Entity Navigation Properties
• Eliminating database update code with Entity change tracking

Enhancing application code

• Automating design reviews with FxCop and Code analyzer
• Reducing User Interface code with Data Binding