I am a computer programmer who spends more than 8-10 hours a day at the desk. I want to know which is the appropriate kind or design of the chair that a computer programmer must use, and what types of exercises to do, so as to avoid back and neck problems?
Assuming there is sufficient room in your cubicle/home office, I would suggest getting an appropriately sized Swiss ball to sit on. In general you'll be moving around slightly while on it, which will help stimulate your core stabilisation muscles. It's also quite easy to do a back bend over the ball, which would be a good idea to do throughout the day to compensate for being hunched forward (even on a ball, there will be a tendency to hunch over). Once you get the hang of it you can also try switching how you sit on the ball. I enjoyed sitting in lotus for 10-15 minutes at a time while on the computer, and kneeling on the ball could also offer up a change, although I found that to be harder to sustain.
If you can get the time to go to a weight room once per week that would also help, doing exercises like deadlifts, squats, presses, dips and pull-ups will put your body under a heavier load than it's normally used to, and should help you be less susceptible to back and neck problems.
Don't Sit All Day
Sitting hunched over a desk or laptop all day is not good for you. At a minimum, take regular breaks throughout the day: walk around the building, get some water, stretch your arms, roll out your neck and ankles, do a few lunges, sit in a third world squat for thirty seconds:
Configure a standing desk, but don't stand all day either: alternate between an hour sitting upright, an hour standing, an hour sitting with your feet up reclining, and so on. Keep good posture while you sit and stand: chest up, shoulders back, maintaining a lumbar curve:
Counteract The Hunch
Your shoulders, hips, and back are all negatively affected by copious desk work. Develop and maintain good mobility with a combination of stretching and strength work. Do yoga or a similar extended stretching-and-mobility routine at least twice a week and (ideally five or more times). Make sure you can touch your toes, fully and properly reach overhead, and do a third world squat.
A strong back is better able to hold good posture. Start strength training with basic movements like squats, lunges, deadlifts, rows, bench and overhead presses, farmer's walks, push-ups, dips, and pull-ups. Add resistance using barbells, kettlebells, or dumbbells when you are ready. Pulling exercises like rows and pull-ups will help your upper back stay in a good shoulders-back, chest-up position during the day. Heavy lifting done properly is also good practice for correct posture.