Getting concrete pool deck done what do I need to look our for?

I would leave a little space at the pool to allow for some shifting (fill in later with a quality rubber caulk). I would dig footings below the frostline to help guard against shifting. Lay out a gravel/sand base to lay the slab on. Lastly, make certain you have a slight slope in two directions so that water (rain and cleaning) do not run into the pool. Good luck.