Cook the rice noodles as per package directions until al dente. Drain.
Heat an inch or two of water in a large skillet over medium heat.
Have all of your ingredients prepped and ready to go for assembly.
Take one of the spring roll wrappers and hold with both hands at the top. Dip the bottom half into the warm water in the skillet until the wrapper just softens (it is easier if it is not too soft). You are looking for it to no longer be hard and to have some flex to it.
Pull the wrapper out of the water and rotate your hands to the now soft side of the spring roll wrapper. Dunk the second, still dry, half into the water and hold until it is soft as well. (Alternatively, you can lay the entire wrapper in the water at once, however I find it more difficult to get it out of the water and laying flat as it folds on itself more easily).
Place the softened wrapper on a flat working surface.
About 2/3 of the way down, layer four thin cucumber slices, slightly overlapping, in the middle. Just above the cucumber, add some of the pickled vegetables (a bundle approximately 1.5-2 inches wide) across the same width as the cucumber slices. Just above the pickled vegetables, add fresh cilantro leaves if desired across the same width as the vegetables.
Place three shrimps right above the cilantro, slightly overlapping the cilantro.
Add approximately 1/3 cup of the rice noodles on top of the cucumber slices. Pour 1 teaspoon of the pickling liquid from the pickled vegetables onto the rice noodles.
Fold both sides of the rice paper wrapper in and over the filling.
Fold up the bottom of the rice paper wrapper over the noodles and continue tightly rolling all the way up.
Repeat with the remaining ingredients to make the rest of the rolls.
Make the sauce by combining the hoisin, sweet chili sauce, rice vinegar, and soy sauce in a small bowl. Whisk to combine and adjust flavors to your preference (more sweet chili sauce for a sweeter sauce, more vinegar for a tangy sauce, etc). You could also serve these with any sauce you prefer.