In a large bowl, combine the shrimp with baking soda, kosher salt, and Old Bay Seasoning. Stir well to ensure the shrimp is evenly coated. Let the mixture sit for 15-20 minutes.

While the shrimp is brining, fill another bowl with cold water and ice cubes.

In a pot, bring water to a boil and add lemon juice. Once boiling, carefully add the brined shrimp and poach for about 90 seconds until pink and opaque.

Immediately transfer the cooked shrimp to the ice bath and let soak for 5 minutes. Drain and pat dry.

In a mixing bowl, whisk together mayonnaise, Dijon mustard, lemon juice, dill, Old Bay Seasoning, celery seed, salt, and pepper until well blended.

Gently add the cooled shrimp to the dressing mixture, carefully folding to ensure all the shrimp are evenly coated.

Cover the salad tightly and refrigerate for at least 2 hours to enhance flavors.