Bring a large pot of salted water to a rolling boil, then add the pasta and cook until al dente, about 8 minutes. Drain and save about half a cup of the starchy pasta water.
While the pasta cooks, heat the olive oil in a large skillet over medium heat until shimmering and fragrant. Add the minced garlic and cook for about 30 seconds, stirring constantly until it turns golden and releases a fragrant aroma.
Add the shrimp to the skillet in a single layer. Cook for 2-3 minutes per side, until they turn opaque, pink, and slightly firm. Remove the shrimp from the skillet and set aside.
Reduce heat to low, then add the grated Parmesan cheese to the skillet along with about half of the reserved pasta water. Stir vigorously to melt the cheese into a smooth, creamy sauce that coats the bottom of the pan.
Return the cooked shrimp to the skillet, tossing gently to coat them in the cheesy sauce. Add more pasta water if the sauce seems too thick, stirring until it reaches your desired silkiness.
Transfer the drained pasta to the skillet, tossing everything together over low heat to evenly coat the noodles in the sauce. Squeeze fresh lemon juice over the pasta for brightness, if using.
Garnish with chopped parsley and extra Parmesan if desired. Serve immediately while hot, enjoying the glossy sauce and fragrant shrimp.
