An obstacle or barrier that may prevent you from accomplishing your goal is:

Depends on what kind of goal.
If I gave a goal of eating 8 hot dogs then a barrier would be a physical will of your body to not eat more. It would be a limit your body can take so it’s different from a mental or other barrier.
If you wanted to cross an area of land but there is a fence in the way then that’s another type of barrier.
Or there are mental barriers. If you wanted to ask someone out to prom, you may be stopped by a mental barrier of self hatred. Feeling like you’re not good enough.

Hopefully this helps!

(on android mobile) click on "me" and then on your profile picture

He would most likely be employed by a gov. agency or homeowner because he has the required skills that have to be known to apply and get hired into those jobs.