Pictures below
Basically, we had an existing deck in place. It stopped short of the edge of the new pool, by some 2-4', depending on where on the "round" pool you measured from.
The railing wound up being about 2-3" higher than the existing deck. The 2 doors leading on to the existing deck would not have allowed the entire deck to be raised that amount. Finally, I wanted the deck slightly above the pool railing, to avoid any chance of tripping on that railing, knocking it loose, etc.
The answer wound up being to build the extension about 6" higher than the existing deck.
I started by using the existing deck as an anchor point, and attaching what amounted to a "riser" to the end of it:
From there, we came out toward the pool with the joists as you can see, and tied them into posts set just a few inches off the pool wall, right at the "corners" of the railing.
2x8 beams were put in at 24" out from the old deck, as you can see in the picture above, then 2x10 fascia boards were attached running parallel to the pool rail. You can see them in the picture above, and the facing side of them here.
Then, as you can see, the deck planks were cut to overhang by 6", which brought them out part way over the railing, so kids can just jump right off, into the pool.
Here's a sort of "overall" look, to give you a feel for the way things are laid out. For reference, the "underneath" shots above were shot from where you see the ladder standing. The dachshund at the left corner of the deck was existing construction.
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So, not the same construction as what you're after, but it does demonstrate the idea of an overhang, and that it's doable out to the dimensions you're talking about.