Preheat oven to 425°F. Line a baking sheet with parchment paper. Toss diced potatoes with olive oil, ranch seasoning, and dill weed. Roast for 45-60 minutes, flipping halfway through, until crispy.

While potatoes roast, cook bacon until crispy and chop. Hard-boil eggs, peel, and chop. Dice dill pickles finely.

In a large bowl, combine roasted potatoes, diced onion, bacon, eggs, pickles, mayonnaise, mustard, dill pickle juice, dill weed, salt, and pepper. Mix until well coated.

Serve warm or chilled, optionally garnished with chopped dill.