Boil the pasta and set aside. As it is boiling, you can start on the rest of your recipe.
Heat the butter and oil in a deep and large saute pan. Once the oil mixture is hot, add your thawed shrimp with 1/2 tsp of Old Bay seasoning.
Cook each shrimp for 2-3 minutes on each side. Once they are completely pink, they are done cooking. Add to a plate and set aside. It is ok if some of your shrimp juices and seasoning is left in the pan. This will help flavor the sausage.
Add your sausage to the pqn. If you are cooking a leaner sausage like turkey or chicken, you may want to add an additional 1/2 tbsp of oil to the pan as you cook your sausage.
Cook the sausage until it is browned on both sides.
Add the shrimp and pasta back to the pan and then add your sauce. Add half of the sauce first and mix it around. Then continue to add more sauce until the pasta is to your liking.
optional: Top with parmesan cheese