In a large pot of salted boiling water, cook the linguine according to package instructions until al dente. Reserve 1/2 cup of the pasta water, then drain the pasta and set aside.
In a large skillet over medium heat, melt the butter and olive oil together. Add the minced garlic and sauté for about 1 minute, or until fragrant.
Add the shrimp to the skillet in a single layer. Season with salt, pepper, and red pepper flakes (if using). Cook for 2-3 minutes on one side until pink, then flip the shrimp over and add the lemon juice and zest. Cook for an additional 2 minutes until fully cooked and opaque.
Gently toss the cooked pasta into the skillet with the shrimp. If the mixture seems dry, add the reserved pasta water a little at a time until reaching your desired consistency.
Remove from heat and garnish with freshly chopped parsley. Serve immediately with lemon wedges on the side for an extra zesty touch.