The A-10 is very rugged and features redundant systems and flying surfaces so it can take a lot of battle damage and still get the pilot home safely. Additional armor is provided in the form of a titanium "bathtub" that surrounds the pilot.
The engines are mounted up high and to the rear to minimize their heat signature as well as inhibit ingestion of foriegn objects that could damage the engines.
Notice the inboard leading edge slats and the large outboard ailerons which also double as speed brakes by opening in a clam-shell fashion with one surface moving upwards and one moving downwards. Twin vertical surfaces at the tail enhance the redundancy in case of battle damage.