Pat the shrimp dry. Use paper towels to remove excess moisture. This helps them sear instead of steam.
Season the shrimp. Toss with a pinch of salt, black pepper, and smoked paprika if using.
Set aside.
Heat the pan. Set a large skillet over medium-high heat. Add olive oil and 2 tablespoons of butter. When the butter is melted and foamy, the pan is ready.
Sear the shrimp. Place shrimp in a single layer.
Cook 1–2 minutes per side until pink and opaque with light golden edges. Do this in batches if needed to avoid crowding. Transfer cooked shrimp to a plate.
Build the sauce. Lower heat to medium.
Add remaining 2 tablespoons butter. Stir in garlic and red pepper flakes. Cook 30–45 seconds until fragrant, not browned.
Add lemon. Stir in lemon zest and juice.
Simmer 30–60 seconds to blend flavors. The sauce should be glossy and slightly thickened.
Return the shrimp. Add shrimp back to the skillet with any juices. Toss to coat for 30–60 seconds.
Taste and adjust salt and pepper.
Finish with herbs. Remove from heat and sprinkle with parsley. Serve with lemon wedges.