Bring a large pot of salted water to a rolling boil. Add the pasta and cook until just al dente, about 8 minutes. Drain and set aside.
While the pasta cooks, pat the shrimp dry and season lightly with salt and pepper. Heat the skillet over medium-high heat and add 1.5 tablespoons of olive oil, shimmering and fragrant.
Add the shrimp to the hot skillet, arranging them in a single layer. Sear for about 2-3 minutes per side until they turn pink and opaque, then remove and set aside.
In the same skillet, add the remaining 1.5 tablespoons of olive oil and toss in the minced garlic and chili flakes. Sizzle for about 30 seconds until the garlic is fragrant and golden, releasing a spicy aroma.
Add the cooked pasta to the skillet, tossing it in the fragrant chili-garlic oil. Cook for another 1-2 minutes, allowing the flavors to meld and the pasta to absorb the spicy richness.
Return the shrimp to the skillet, squeezing half a lemon over everything. Toss gently to combine and heat through for about a minute, ensuring the shrimp stay tender and the flavors intensify.
Taste and adjust seasoning with salt, pepper, or more lemon if needed. Sprinkle chopped parsley over the dish for a fresh, herbaceous finish.
Serve immediately while hot, with a final squeeze of lemon and a sprinkle of chili flakes for extra heat and brightness. Enjoy the vibrant, spicy seafood pasta!