in reply to perl certification
I can certainly tell you this: if you have been using Perl “for more than 4 years,” then you will probably do better if you can just find a way to explain what you did, and what might be the business value of that experience to a future employer. (Never mind the recruiters... what do they know, anyway?) This is a craft that you learn by doing. Therefore, my number-one and number-two questions would be: “what did you do?” and, “show me your code.”
A certification is ... a product. It is a product that is sold to people like you. An affirmation, if you will. A pat on the back. An attaboy. A feeling of accomplishment, of having successfully crossed the finish-line. But, was anybody actually in the grandstands when you did it? To me, if I were a prospective employer, it does not really tell me anything objectively. But if I can see your work, and hear you talking about it, and get you into some serious conversation, then I can learn a great deal about you in a few minutes’ time. Far more than I would ever learn from a piece of vellum with gothic-font writing on it. And if I am about to make a multi-thousand dollar purchase (of your time and expertise), that matters.
Analogy: “So you say you’re a ‘certified cabinetmaker.” Okay, cool. Whatever. Do you have some references from recent customers whom I can call?” If I am about to get into a boat and set sail, I want to talk to former passengers ... not calligraphers.