Bring a large pot of generously salted water to a boil. Add the linguine or spaghetti and cook according to the package instructions until al dente. Before draining, reserve about 1 cup of the starchy pasta water, then drain the pasta.

Pat the shrimp dry with paper towels and season lightly with salt and freshly ground black pepper. Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Add the shrimp in a single layer and cook for about 1–2 minutes per side, until pink and just opaque. Transfer them to a plate so they do not overcook.

Reduce the heat to medium and add the remaining tablespoon of olive oil along with the chopped shallots. Cook for about 2 minutes, stirring occasionally, until softened. Add the minced garlic and red pepper flakes, then cook for another 30 seconds until fragrant.

Pour in the white wine and bring it to a gentle simmer. Scrape up any flavorful browned bits from the bottom of the skillet and let the wine reduce for 3–4 minutes, until slightly concentrated.

Add the butter, lemon juice, lemon zest, and about ½ cup of the reserved pasta water. Stir until the butter melts and the sauce becomes glossy. Taste the sauce and season with salt and black pepper as needed.

Add the drained pasta to the skillet and toss thoroughly to coat the strands in the garlic butter sauce. If the pasta looks dry, add a little more reserved pasta water until the sauce clings smoothly to the noodles.

Return the shrimp and any accumulated juices to the skillet. Toss gently for about a minute, just until the shrimp are warmed through. Stir in the chopped parsley and adjust the lemon juice, seasoning, or red pepper flakes to suit your taste.

Divide the shrimp scampi pasta among warm serving bowls. Garnish with extra parsley and serve immediately with lemon wedges on the side.