Place 5 pounds Russet potatoes into a large pot and cover with cold water. Place the pot over medium-high heat and bring to a boil. Cook until fork-tender, about 20-25 minutes.
Drain the potatoes using a colander. Transfer the potatoes back into the pot and allow them to cool slightly.
In a large serving bowl, whisk together 2 cups mayonnaise, 3/4 cup pickle juice, 1 teaspoon salt, 1 teaspoon black pepper, 1 teaspoon garlic powder, and 1 teaspoon onion powder until smooth.
Add the potatoes, 1 medium yellow onion, 3 stalks celery, and 8 large hard-boiled eggs to the serving bowl. Gently toss to coat everything in the dressing.
Cover and refrigerate for at least 1 hour for the best flavor, or until ready to serve. Sprinkle with fresh parsley for garnish and enjoy!
Notes
Cool the potatoes before dressing for the creamiest texture.
Use dill or sweet pickle juice, depending on your taste.