I always had a problem with the term 'User Experience (UX)' being used to describe a particular discipline - not that I don't agree with the fact that's what they are predominantly concerned with. I just don't like that it seems to imply that other disciplines are NOT about user experience.
I am a graphic designer, and it is definitely (should be) about user experience. But that's probably very obvious - so I didn't complain.
And there are developers.
I recently read an excellent blog about the UX developer by Leisa. She makes a point that some front end developers are so in tune with the idea of user experience, they can be called UX developers for their contributions.
I cannot agree more. But I also agree with one of the comments the article has - "UX dev is just a good front end dev". Because of front end development's closeness to users, in the same way as the visual design and site architecture, it has to take user experience into consideration to do a great job.
What about the back end devs?
You might think, well, it's not important that they understand UX - after all they are not creating direct touch points to user journeys.
There would be no 'you can't do that because it's not built / structured / stored in the right way', because they understand the importance and WHY you're asking certain things to happen. They would be coming up with alternatives to achieve your goal, or find the way around it. They could suggest you a new way of doing things which you thought technically not possible (or plainly not thought of), because they understand the user journey and user experience principle. It's the same in any disciplines - you can solve problems so much better / quicker when you know WHY something needs to happen rather than just WHAT needs to happen.
So my conclusion is - UX devs definitely exist and it includes ALL devs. If in doubt, try working with one. It's so good, you don't want to work without them ever again. :-)