Using the julienne blade of a mandoline, slice zucchini into long, thin strips. Transfer zucchini to a colander set over a mixing bowl. Toss zucchini with salt. Let stand 15 minutes at room temperature.
Gently squeeze zucchini to extract excess water. Transfer to a bowl and toss with just enough dressing to evenly coat the zucchini. Season with fleur de sel and serve.