The secret to not having back pain or other health problems due to office work is very simple:

Move!

Furniture that enables you to move throughout the day:

A standing desk. Use it to alternate between standing and sitting throughout the day.

Get one of these to seamlessly transition between sitting, near standing and standing: https://www.varierfurniture.com/en/move

Or these, they will make you maintain good posture: https://www.varierfurniture.com/en/variable

Using these will also train your core muscles ever so gently, giving you better posture and preventing back pain. Good posture will also make you more attractive to your preferred gender, so that’s a plus.

If you are not in a healthy range as far as the BMI is concerned, obviously fix that first. No furniture can compensate for overloaded joints.