When in the web domain, I find that the sought after skill is connected to what the user sees. Be it graphical elements, css art, user interface design, content strategies, copywriting or mobile adaption, to mention some examples – when looking for help, a buyer tends to view the needs from the perspective of the user.
This is, of course, a necessary and good thing. But it poses some challenges for those of us working as developers.
37Signals advocates that everybody should be writers, and makes sure that the designers are the team leaders. I think this makes sense, especially for a distributed company. You will need to communicate, and the better you do it, the better off you are, and the more you get done. And last but not least, the better you communicate, the better you are at enabling others to get stuff done.
Designers as team leaders are a sensible idea. They are in charge of the communication. They might not always be the ones that are capable of implementing a complex algorithm, but they are the ones that bind together users and developers.
But I digress.
If you look at how the terms are used in everyday-lingo, the separation is even simpler. Developers make software, or web pages. Designers make them look good.
The lines are more blurry that that. Designers often implement their designs, and developers more times than not need to implement designs without support of artists. The skills aren’t mutually exclusive either.
But you’ll need to know what you are looking for. Know that more times than not creating a website is more than a single-person job, if it is to be done well. And, even though most is able to a certain degree to do both, be specific. Do you want a search interface, or the algorithm?