While pasta is cooking, cook pancetta in a pan until crispy. Remove pancetta and set aside, reserving the rendered fat.
In a bowl, whisk together eggs, Pecorino Romano, Parmesan cheese, and black pepper.
Drain pasta, reserving some pasta water. Add pasta to the pan with the pancetta fat.
Remove pan from heat. Quickly add egg mixture to the pasta, tossing constantly to prevent the eggs from scrambling. Add pasta water if needed to create a creamy sauce.