Bring 4 qt. water to a boil in a stockpot over high heat. Add 1/4 cup salt; return to a boil. Add pasta; boil, stirring occasionally, 11 minutes. Add peas, and cook 3 minutes or until peas are tender. Drain, reserving 1 cup pasta water.
Melt 2 Tbsp. butter in a medium skillet over medium heat; add breadcrumbs, and cook, stirring often, 4 minutes or until brown. Add 1 tsp. zest, and cook, stirring constantly, 2 minutes. Remove from heat.
Sauté shrimp in remaining butter in stockpot over medium-high heat 4 minutes or just until shrimp turn pink. Stir in lemon juice and 1/2 cup reserved pasta water. Stir in pasta mixture. Stir in up to 1/2 cup pasta water until desired consistency is reached. Transfer mixture to a platter. Top with panko, parsley, black pepper, and remaining lemon zest.