Based on your example, I think the word you want to use is the noun "experience." If that is correct, you would say something like, "I have ten years experience in the field of system development."
The other choice would be to use the adjective "experienced." In that case you could say, "I am an experienced system developer."
Using experienced as a verb, you could say, "I have experienced many aspects of a system development career." (Awkward sounding)