Cook the elbow macaroni according to package instructions until al dente. Drain and rinse under cold water to cool.

In a large bowl, combine the mayonnaise, Dijon mustard, apple cider vinegar, garlic powder, onion powder, salt, and black pepper. Mix well until smooth.

Add the cooled macaroni to the bowl with the dressing and stir to combine.

Fold in the diced celery, red bell pepper, red onion, sweet pickle relish, and chopped hard-boiled eggs.

Gently mix until all ingredients are evenly coated with the dressing.

Cover and refrigerate for at least 1 hour to allow the flavors to meld.

Before serving, sprinkle with chopped parsley for garnish and give it a gentle stir.