Bring a medium pot of water to a boil and poach the shrimp for 2-3 minutes until they are pink and opaque.
Immediately drain the shrimp and transfer them to a bowl of ice water to stop the cooking process and ensure a firm texture.
Once chilled, pat the shrimp dry and chop them into small, bite-sized pieces.
In a large glass bowl, whisk together the lime juice, olive oil, chili powder, sea salt, and black pepper.
Add the chopped shrimp to the bowl and toss thoroughly to ensure every piece is coated in the citrus marinade.
Stir in the diced red onion, tomato, minced jalapeño, and fresh cilantro.
Gently fold in the diced avocado just before serving to keep the cubes intact and creamy.
Let the mixture sit in the refrigerator for 10-15 minutes to allow the flavors to meld together before serving.