If it's posture related, here's more free advise: try sitting on stools rather than on chairs with a back, and sit up straight and keep your arms actively powered while typing (not laying on a surface). Also, when you need to think for a minute get up and walk around.
A stool without a back would be very uncomfortable, but I do have ergonomic chairs (Herman Miller Aeron) which should do a decent job from what I understand.
The point of sitting on a stool is that you have to use your core strength to sit up straight, and using that core strength reduces all sorts of pain in back and neck.
I didn't start doing that (sitting on stools) till I had been meditating for a long time, so it wasn't that different than sitting on the floor in half lotus position, which I had extensive practice doing.
I've been doing it for >10 years now; I will confess that when I have a meeting in a meeting room with proper chairs, I do really enjoy the chair back. It's all about using your body in a variety of ways.
