Scott Hanselman recently posted a blog entry seeking a senior developer to work at Corillian. His post has some pretty specific requirements about the knowledge needed by a potential applicant. Scott made a comment that some people find his requirements to be too difficult or totally irrelevant. Jeff Atwood talks about the flip side of this coin which is stupid interview tests.
I have pretty strong feelings on this front. I have conducted a ton of interviews over the last several years and found that our industry is loaded with a ton of programmers with inflated job titles. I have run across people who have only been out of school for a couple years who claim to be "Senior" programmers. I have seen others who think that because they have been programming for 20 years that they qualify as a Senior programmer.
I come from a different school of thought. I believe that the number of years of programming experience has little bearing on whether you are a senior programmer or not. If your 20 years of experience consists of writing software applications which would be good candidates for The Daily WTF, then you do not fit my definition of a senior programmer. I could be the best programmer in the world when working with ASP.Net, but I would never claim to be a Senior PHP developer. I may have skills which are transferable, but more than likely, my first couple of PHP applications would likely not exhibit good PHP programming practices. My applications would likely look like ASP.Net applications written in PHP. This is similar to the problem encountered by many VB programmers who move to VB.Net. Many of them write procedural VB.Net with properties, methods and classes liberally sprinkled on top.
When interviewing candidates I like to start with a set of questions that give me some points from which I can drill down to truly assess the candidates understanding of programming in general and the specific technology needed for a given project. I look for both breadth and depth and don't worry about someone knowing or not knowing one specific question.
At first glance, the question referenced in Jeff's blog may seem like a case of trivial pursuit that has no bearing on a candidates skill, I would disagree. If you look at the full back and forth you see that the candidate has a good understanding of the file copy task. He/she realizes that there are many issues that must be addressed in order to complete the task. I would love to have a candidate who would ask these questions. It says that they are thinking about the problem and how to solve it.
So what are some typical questions I would ask of an applicant for a Senior ASP.Net developer? This is an excerpt from a questionaire I used to screen candidates for a project lead position (note: I ask these questions in person so I can ask followups depending on their answers):
- What is Reflection?
- What is the difference between an abstract class and an Interface?
- What is a delegate?
- Name two ways to assign events?
- What are attributes?
- How is ADO.net different from ADO?
- What is a dataadapter, dataset, dataview and datareader?
- What is the GAC? How do you put your code in the GAC?
- What is side-by-side execution?
- What is MSIL?
- What is a code-behind file?
- What is the difference between User Controls and Server Controls?
- Why would you build one versus the other?
- What is the purpose of the Machine.config file?
- Web.config file?
- What is an HTTPModule and an HTTPHandler? Give an example of how each one might be used.
- What are the differences?
- What is viewstate?
- What is the difference between WebControls and HTMLControls?
Now some of these questions may be too trivial or too simple, but I found that the answers given could lead into whole new discussions. I also found that the best candidates were not afraid to admit that they might not know the answer to a specific question. I would rather have a developer who knows their own limits versus one who thinks that they know all there is to know about a given topic.