Preheat oven to 400°F.
Toss wedged potatoes in olive oil, smoked paprika, garlic powder, oregano, black pepper, onion powder, and salt. Transfer to a baking tray and roast for 40 minutes. Allow to cool.
While the potatoes bake, bring a large pot of salted water to a boil. Add the corn and cook for 3-4 minutes. Drain the water and cool.
Make the butter sauce. To the melted butter, add cajun seasoning, old bay seasoning, smoked paprika, oregano, garlic powder, onion powder, lemon pepper, cayenne powder, minced garlic, and lemon juice. Mix together.
In a large sheet pan, add the shrimp, corn, potatoes, and sausage. Pour the butter sauce over the top and toss to evenly coat.
Bake for 15 minutes at 400°F.
Once out of the oven, garnish with parsley leaves and lemon wedges. Serve!