Preheat the oven to 425 degrees Fahrenheit and line a large baking sheet with parchment paper.
Pat the potatoes dry with paper towels, then toss them with olive oil, salt, pepper, garlic powder, and paprika until evenly coated.
Arrange the potatoes cut side down on the prepared baking sheet and roast for 35-40 minutes or until deeply golden and crispy.
Allow the potatoes to cool for about 10 minutes so they stay crisp while mixing.
In a large bowl, whisk together the mayonnaise, Dijon mustard, apple cider vinegar, sugar, salt, and black pepper until smooth.
Add the celery, red onion, dill, parsley, and bacon to the dressing and stir to combine.
Gently fold the roasted potatoes into the dressing mixture until evenly coated.
Serve warm for the crispiest texture or chill slightly before serving.