Dragon Age does do level scaling, but it isn't particularly strict. If you go to a certain place when you're level eight, the encounters are going to be beatable, but they'll still be harder than if you go there at level 18. You fight a lot of the same creatures throughout the game, but the designers intended for you to feel more and more badass against them as you grow in power. By the end-game, when you're around level 20 or so, you've got a lot more mass-combats against level 10s whereas when you're level 10 you're more likely to face five or six monsters of levels 8-12.