I am a developer with expertise in Qt GUIs. I was assigned to it when I was a fresher in a different company. But overtime I've started to hate working on the technology.
The reason simply being that I get constant changes which are never documented (despite my effort). The timelines are not moved. When pointed out, I am told that apparently this was part of the original estimate. Apart from the above mentioned, GUI is simply speaking given the least priority and importance while it is also the first thing the user sees.
Basically, over the 2 companies I've worked with(one being a government PSU; in India, you don't leave them. I still did), the teams are understaffed while expectations are high. Last but not the least, the projects are always ancient with zero documentation and large number of permutations for testing (which are unknown to everyone as GUI people don't stay). One requirement generally means a hundred more changes (the requirement to create a building in 3D also entails the ability to delete it for instance).
Also, I have a personal amazement for back-end work. I like to be the guy who creates all kinds of data structures and what not.
The problem is that my CV contains different ways for using Qt GUI. This prevents me for applying for a good C/C++ coder job (The interviewers basically state that I don't have any experience with C/C++. No technical questions asked). My current company needs more Qt people (no one is willing to learn it and the freshers whom I've trained somehow magically end up getting a better paying job in Qt at a different firm) so, they won't let me switch no matter what.
Edit: Forgot to mention, I've never seen a position for a senior developer in the field in my area.