Barn on a hill

I want to build a barn, but I am not working on a level 2015 cement pad… in fact i do not get along with cement in general. It looks so easy, but has hidden costs and problems etc. Before I leap in, I would like to describe the site and my plans & see if anyone can poke holes or point out better ideas. First, the back wall about six feet higher than the front wall. The good part is that it is a rock ledge, and gravel run. But what do I use as a foundation? If I were doing a timber frame i would set it on plinths, but i am not likely to have that option…