Bring a large pot of salted water to a boil, then add the pasta and cook until al dente, about 8-10 minutes. Drain and set aside, reserving a little pasta water.
While the pasta cooks, zest the lemon and juice it, keeping both separate. Mince the garlic cloves finely.
Heat a skillet over medium heat and add olive oil. Once shimmering, toss in the minced garlic and sauté until fragrant, about 30 seconds, until golden and aromatic.
Add the shrimp to the skillet and cook for 2-3 minutes per side, until they turn pink and opaque. Use tongs to turn them gently and watch for a slight curl.
Lower the heat and add the butter to the skillet, stirring until melted and glossy. Pour in the lemon juice and sprinkle in the lemon zest and red pepper flakes. Let the sauce simmer gently for 1 minute, releasing a bright, citrusy aroma.
Add the cooked pasta to the skillet, tossing gently to coat it with the lemony sauce. If needed, splash in a bit of reserved pasta water to loosen the sauce and help it cling to the noodles.
Cook everything together for another minute, allowing the flavors to meld and the sauce to thicken slightly. Taste and season with salt and pepper as needed.
Serve immediately, garnished with additional lemon zest or herbs if desired, and enjoy the vibrant, buttery, citrusy flavor of this bright dish.
