Bring a pot of salted water to a boil. Add the macaroni and cook according to package directions until just al dente (about 7–9 minutes).

Drain the pasta and rinse briefly under cold water to stop cooking and cool it faster. Drain well and transfer to a large mixing bowl.

In a medium bowl, whisk together the mayonnaise, sour cream, and pickle juice until smooth and slightly glossy. Taste and adjust — the dressing should be tangy but not overpowering.

Add the chopped dill pickles, diced red onion, and chopped fresh dill to the bowl with the pasta. Pour the dressing over the pasta and toss gently until everything is evenly coated.

Season with salt and freshly ground black pepper to taste. Remember that pickles and pickle juice are salty, so season lightly.

Cover and refrigerate for at least 30 minutes before serving to let the flavors marry; 1–2 hours is better if you have time.