In a large stock pot over high heat, boil the potatoes and eggs. Set a timer for 13 minutes. Once the timer goes off, remove the eggs and quickly chill them in ice cold water. Continue to cook the potatoes until they are fork tender, about 7 additional minutes. (20 minutes total for the potatoes)
Once the potatoes are thoroughly cooked, drain and place them in the ice water bath to cool.
In a 4 quart saucepan, boil the macaroni noodles for 7-9 minutes. Drain, rinse, and set aside.
Peel and dice the eggs and potatoes.
In a large mixing bowl, stir to combine the chopped eggs, potatoes, macaroni noodles, mayonnaise, mustard, salt, pepper, diced celery, diced onion, shredded carrot, and salad shrimp.
Refrigerate for 3 hours or overnight.
When ready to serve, stir the salad add additional mayonnaise if needed. The potatoes and macaroni will draw in some of the mayonnaise while refrigerated.