Cook the elbow macaroni according to package instructions until al dente. Drain and rinse under cold water to cool. Set aside.
In a medium saucepan, place the eggs and cover them with water. Bring to a boil, then cover and remove from heat. Let sit for 12 minutes. Afterward, transfer the eggs to an ice bath to cool for about 5 minutes. Peel the eggs and chop them into small pieces.
In a large bowl, combine the mayonnaise, Dijon mustard, apple cider vinegar, garlic powder, onion powder, salt, and pepper. Mix until smooth.
Add the cooked macaroni, chopped eggs, diced celery, diced red onion, and sweet pickle relish to the bowl. Stir gently until all ingredients are well combined.
If desired, fold in the chopped parsley for added freshness.
Cover the salad and refrigerate for at least 1 hour before serving to allow the flavors to meld.