Bring a large pot of generously salted water to a boil. Cook the linguine according to package instructions until al dente. Reserve at least 1 cup of pasta water before draining. Drain and set aside.
12 ounces linguine or spaghetti
Pat shrimp dry and season with salt and pepper. Heat olive oil in a large skillet over medium-high heat. Add shrimp in a single layer — work in batches if needed — and cook 1–2 minutes per side until pink and just cooked through. Remove to a plate.
1 tablespoon olive oil, 1 pound jumbo shrimp
Reduce heat to medium. Add some butter to the same skillet. Once melted, add garlic and chili flakes (if using) and sauté for about 1 minute until fragrant — don’t let the garlic brown.
6 garlic cloves, ½ teaspoon chili flakes, 3 tablespoons unsalted butter
Pour in the white wine and let it simmer for 2–3 minutes, scraping up any browned bits, until mostly cooked off.
½ cup dry white wine
Add the drained pasta to the skillet along with some reserved pasta water. Toss to coat, adding more pasta water as needed — the sauce should be loose and glossy. Off the heat, stir in the parmesan and toss until melted and silky.
½ cup reserved pasta water, ⅓ cup parmesan
Return the shrimp to the pan. Add the lemon zest and juice and parsley. Toss for 30 seconds. Add the remaining 1 tablespoon cold butter and toss until glossy. Taste and adjust salt and pepper. Serve immediately with extra parmesan on the side.
1 lemon, ¼ cup fresh flat-leaf parsley, 1 tablespoons unsalted butter