That is quite a broad question. Do career departments exist that just do wildland firefighting?
I have done quite a bit of it in my life, as a member of a department whose AOR included plenty of areas that liked to burn year-round.
It is not for everyone, it tends to be as physically-demanding (if not, sometimes, moreso) than interior firefighting, and along with that you have a very high potential for lower body injuries from such things as falling into pits you may not see, ending up chest-deep in mud with 5 gallons of water on your back, miscalculating distances due to smoke obscurance, UXO near/on military bases, and other unique hazards and considerations. Wildfires are completely different animals, situations that can literally change in a second with no advance warning (not that interior doesn't share the same chances), you are truly at the mercy of mother nature and anything can happen that has never been covered in a textbook before.
Here's yours truly, last spring, having some fun in the (obscured) sun!! (Note: photos are not posed and I was unaware of how close the photographer was to me...media was allowed right into the thick of things due to difficult logistics at the scene)