Bring a large pot of salted water to boil for the pasta. While waiting, pat the shrimp dry with paper towels and season with salt and pepper.

Cook pasta according to package directions until al dente. Before draining, reserve 1/2 cup of pasta water.

In a large skillet, heat olive oil over medium heat. Add garlic and red pepper flakes (if using), cooking until fragrant, about 1 minute.

Add shrimp to the skillet in a single layer. Cook for 2-3 minutes per side until pink and opaque. Remove shrimp from the pan and set aside.

In the same skillet, add lemon juice, zest, and butter. Stir until butter melts and sauce begins to simmer.

Add cooked pasta to the skillet, tossing well to coat with the sauce. If needed, add reserved pasta water a little at a time to create a silky sauce.

Return shrimp to the pan and add chopped parsley. Toss everything together until well combined and heated through.