Comment by wakawaka28

The thing about specific needs is that they are usually narrow. You could throw darts at the dartboard of problems, working on very narrow problems for years and never get a job solving any of them. If a problem calls out to you and you won't stop until you get a job with it, then the effort could be worth it. But sometimes, even if you get THE job, you'll have a slight twist in constraints that makes most of your prep go by the wayside.