Mar 25, 2010
The best way to understand the depth of knowledge a candidate might have in design pattern is by asking these questions...
1. What are all design pattern you have used in your project?
2. Explain a scenario where you have applied <any pattern name told in previous answer>PATTERN_NAME? and why did you applied this pattern?
3. How long you have been using design patterns for the projects you had worked?
May 21, 2010
1.which patterns you used?
2.why that pattern you used?
3.what are the benefits of design patterns?
4.In which situation you will use say singleton pattern(any other patterns)?
Aug 19, 2011
First you need to ask them if they know the basic OO principles: SOLID and GRASP.
The Design Patterns are nothing more than concrete implementations of these principles.
Then you delve into the Design Patterns specifics.
In real world very often you may not use a Design Pattern as it is in a book, what matters is to know and understand the principles and the ideas behind OO. Then you can do a good job when you architect and design an application.