Preheat oven to 425°F. Line a large sheet pan with foil.
Cut sweet potato into 1-inch cubes, bell pepper into 1-inch strips, and zucchini into half-moons. Slice sausage (use any cooked sausage — kielbasa, Italian, chicken sausage) into coins.
Toss vegetables with olive oil, salt, paprika, and Italian seasoning until well coated.
Spread everything in a single layer on the sheet pan — do NOT pile it up. Use two pans if needed. Crowding is the enemy of roasting.
Scatter sausage slices among the vegetables.
Roast 25–30 minutes, flipping once halfway, until vegetables are tender and caramelized at the edges.