Here's a picture of the old pool where you can see how the yard slopes. It doesn't look like much where the pool is, but remember 40 tons of dirt was removed to level the pool area.
Here's one of the framework going up on the new pool. You can see the block retaining wall keeping the rock dust we used to build up the low area in place. We didn't know anything about rock dust when we built the first pool but made good use of it under the new one. Easy to smooth out level and packs like concrete when dampened.
This is a picture of the new pool finished. You can see from the way this side of the deck sits on undisturbed ground how off level the ground was to start. Under the deck the ground is tapered so the pool walls are not in ground contact.
I don't know if I've been of any help to you, but I hope I have!
On a sort of unrelated matter, notice that the first deck was treated lumber and the new one is composite. If you are planning on a pool deck I strongly recommend the composite. We hated the wood deck, the composite is well worth the higher price! It sucks getting a splinter in your foot at the pool.