Set the noodles to boil while you prep the sauce and vegetables. Cook as per package instructions, drain once cooked, reserve 1/2 cup noodle water and massage drained noodles with a little oil after to avoid them sticking.
In a small bowl, mix the soy, gochujang, sugar and lemon juice. Thin out with 2-4 tbsp noodle water since gochujang is quite thick and sticky. Taste the sauce and adjust the ingredients if needed as per your liking. At this point it should taste bold and salty. Keep ready.
In a 12 inch pan, heat up 1 tbsp oil on medium.Layer the shrimp, sprinkle some salt and sear/cook them for 2-3 minutes each side depending on the size of your shrimp. Take out in a plate.
Add another tbsp of oil and add the sliced zucchini next,sprinkle pinch of salt and quickly saute on high for 2-3 minutes so as to not overcook it. Transfer in the same plate as shrimp.
Add the rest of the oil to the pan and heat up on high. Add the shallots and white scallion parts for 2 minutes till they are soft. Work quickly now and next add the sliced garlic and saute for 30 minutes. Add the sauce mix that we prepped now and cook it for a minute or so with shallots and garlic till the sauce starts bubbling.Keep a close eye since the sugar caramalizes fast.
Add the noodles next along with shrimp & zucchini and toss everything very well so that its coated in sauce. Taste and adjust the salt. Cook for 3-4 minutes and you can use reserved noodle water (add slowly) if you feel that everything is a bit thick.
Sprinkle toasted sesame seeds and green scallion parts and serve immediately.