Prep the zucchini: Spiralize the zucchini into noodles.
Place them on a clean towel, sprinkle lightly with salt, and let sit 5–10 minutes to draw out moisture. Gently pat dry.
Season the shrimp: Pat shrimp dry. Toss with a pinch of salt, black pepper, and a bit of lemon zest.
Heat the pan: Set a large skillet over medium-high heat.
Add 1 tablespoon olive oil.
Cook the shrimp: Add shrimp in a single layer. Cook 1–2 minutes per side until pink and just opaque. Remove to a plate; do not overcook.
Sauté the garlic: Lower heat to medium.
Add remaining 1 tablespoon olive oil and the butter. Stir in garlic and red pepper flakes. Cook 30–60 seconds until fragrant and lightly golden, not brown.
Add zucchini noodles: Toss zoodles into the pan with the garlic oil.
Cook 1–3 minutes, tongs in hand, until just tender but still springy. Season with salt and pepper.
Finish with lemon and shrimp: Return shrimp to the pan. Add lemon juice and a bit more zest.
Toss to coat and warm through, about 30 seconds.
Garnish and serve: Turn off heat. Sprinkle with parsley and, if you like, a light dusting of Parmesan. Taste and adjust salt, pepper, and lemon.