Personally, having an ergonomic workspace works the best for me. I used to get pain in my neck, shoulders, wrists, and even the joints in my hands. Everyone is different. Here is what I recommend and do myself.
* Get a good chair. I bought a secondhand Herman Miller Mirra chair from an office furniture liquidator.
* Buy a sit/stand desk. I have one and while I rarely use it in the standing configuration, the easy control over the hight of my desk is very useful.
* Go tenkeyless. Full-size keyboards require you to move your arm to reach the mouse and put force you to work in awkward positions. For me, getting a Kinesis Advantage2 LF keyboard was the most important improvement I made. I can never go back to any other kind of keyboard now. I also bought an external tenkey pad that keep on the left side of my keyboard to minimize arm movement.
* Use a trackpad instead of a mouse. This might not apply to everyone, but I tend to grip a mouse too firmly and it causes pain in my fingers and wrist. I tried a Logitec trackman, which is an improvement, but I get pain in my thumb. What works best for me is an Apple Magic trackpad.
* Do you work on on monitor and have it sitting directly in front of you. Make sure it is adjustable. Extra monitors mean you have to turn your head to use them. I use my laptop display as an extra monitor and only put things that I check infrequently and need to interact with little on that display while working.
* This one might be unpopular, but learn the VIM keybindings and use them in your IDE. This will reduce how often you need to use the mouse once you get the hang of it.
Last but not least, work from home. Every employer I have had, big and small, had sorry excuses for ergonomic office equipment. Getting something better always seems to involve some kind of political drama. I'm much happier with my personal equipment that suits my needs.