Peel and dice potatoes into uniform chunks, then submerge in cold water.

Bring water to boil, then reduce heat and simmer for 10-15 minutes until fork-tender.

Drain and chill the potatoes in an ice bath for about 5 minutes until cool.

In a mixing bowl, combine mayonnaise, vinegar, mustard, salt, and pepper; whisk until smooth.

Add cooled potatoes, celery, onion, and hard-boiled eggs to the dressing and gently toss.

Cover and refrigerate for at least 4 hours or ideally overnight.