Begin by filling a large pot with salted water and bring it to a rolling boil. Add the dry macaroni noodles and cook according to the package instructions until al dente, about 8-10 minutes. Drain and let cool.

In a spacious mixing bowl, combine the cooled macaroni, diced corned beef, cubed Swiss cheese, drained sauerkraut, and chopped dill pickles. Fold gently with a spatula.

In another bowl, whisk together the thousand island dressing, mayonnaise, Dijon mustard, and optional sauerkraut brine until smooth.

Pour the dressing over the pasta mixture and stir gently to coat everything evenly.

Cover the bowl and refrigerate for at least 1 hour, or preferably overnight.

Before serving, stir the salad gently and adjust seasoning with salt and pepper if needed. Serve cold.