Prepare shrimp by thawing completely (if frozen) and making sure they are peeled and deveined. Place shrimp on a few layers of paper towels and blot with additional paper towels so that they are as dry as possible.
Sprinkle salt and pepper over both sides of the shrimp.
Bring a large pot of salted water to a boil and cook linguini to desired tenderness. Reserve one cup of the pasta water and drain pasta the rest of the way.
Meanwhile, melt 4 tablespoons of butter in a large saucepan or skillet over medium heat. Add the garlic to the pan and saute for about 30 seconds.
Add shrimp to the pan in a single layer. Allow them to cook without stirring until they are fully pink and slightly golden brown on one side (about 2 minutes). Quickly flip to the other side and continue cooking another 1-2 minutes until they are pink/opaque all the way through. Immediately remove from skillet.
Melt the remaining 4 tablespoons of butter in the same pan. Add lemon juice and whisk in heavy cream. Bring the sauce to a low simmer.
Add parmesan cheese and whisk until sauce is smooth and cheese is fully melted.
Add cooked pasta and up to 1 cup of reserved pasta water into the sauce. Stir to coat pasta. Add the shrimp back into the pan just long enough to reheat gently.
Serve immediately with lemon wedges, chopped parsley, and a sprinkle of parmesan cheese, if desired.
Notes
You really want to sear the shrimp by getting the garlic butter nice and hot and ensuring that the shrimp are dry and pre-seasoned. Put them in the pan without a lot of stirring or moving them around. Work in batches if you can’t fit all of the shrimp in a single layer. Don’t crowd them. You don’t want to boil them or overcook them. The whole process takes 4-5 minutes tops.
The pasta water helps break up the pasta and the sauce and keep it from getting too thick and clumpy. You can adjust the amount of pasta water by adding it a little at a time. As the sauce cools, it will thicken also. I found about 1 cup of pasta water to be great.
Shrimp vary in size. They’re labeled by how many shrimp are in a pound - so the lower the number, the larger the shrimp. I used 21-25 per pound shrimp.