- we can quickly gain knowledge about what's new going on - what new technologies are currently mostly used, what key knowledge is important
- we're getting used to stressful conversations about our carrier and personality - it would be no surprises later
- we can take free tests on different technologies
Having all this three points we can quickly identify our weak points and in which areas we need to improve ourselves. Of course this technique is rather considered in long-term (a year or more) but can be very benefitial.
Mainly we can easily get through the first step of recruitment in any company, beacuse it's rather being done by someone that can barely judge our true skills (no offence). Usually this first contact person we are speaking with, knows nothing about technology and IT. It's easy to pass this first step because it's mainly being done by recruitment and human resources companies.
Second (optional) step is harder - we are speaking (usually by the phone) with someone from our potential employer. It depends on company but mainly this person knows much more about candidate requirements and technology. But it's relatively easy to pass also this step. Of course we must have some knowledge about given topic, but mainly there are questions about what we've been doing in our previous company.
Last step is the most difficult one - we have an interview with technical person - lead programmer or somebody similar - master technical guru of the company / team. Here we have the essentials. We are being asked to solve difficult problems - we can identify where are our weak points. Typically we're taking some tests - we can check what we need to learn, and what we're really good at. After all, even when we've failed at some tasks we can ask questions about how it should be done and what is the answer.
Tests and questions are usually similar between companies, so it's easy to learn just by doing them. I had a situation that I had scheduled four interviews in a row in one day (the third step ones). First one was a disaster - I know that I really didn't fit to that position but I wanted to try for fun. I learned a good lesson from it, asked couple of questions and left unemployed but smarter. The next two interviews haven't gone as bad as the first but still I was not satisfied with the results. Before the last one I'd been after session of three exhausting recruitment sessions on which I'd learned a big set of new things and solutions. It's payed me a lot, because on this last one I've been asked similar questions to these from the three earlier (failed) conversations - it was just a piece of cake to asnwer to all of them.
One day of intense interviews can give you a lot of experience. It's really worth sending cv to big number of companies from time to time. Actually regular searching through job offers can even give you some knowledge about what capabilities are most wanted on the job market.