Place potatoes into a large potand cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until barely tender, about 10 minutes. Drain. Rinse potatoes with cold water to cool completely; drain.
Stir mayonnaise, pickles, eggs, red onion, celery, mustard, vinegar, salt, and pepper together in a large bowl. Fold potatoes into the mayonnaise mixture. Top with green onion.