Boil salted water in a large pot and cook the macaroni noodles for 7-9 minutes until al dente, then drain and rinse with cold water.

In a mixing bowl, combine diced corned beef, cubed Swiss cheese, sauerkraut, and diced dill pickles, mixing gently.

In another bowl, whisk together Thousand Island dressing, mayonnaise, Dijon mustard, and sauerkraut brine until smooth.

Combine cooled macaroni with the meat and cheese mixture, then pour dressing over and toss to combine.

Add salt and pepper to taste, mixing gently to distribute seasoning evenly.

Cover and refrigerate for at least 1 hour or overnight for best flavor.