Bring a small pot of water to a boil, add the shrimp, and poach for 2-3 minutes until they are pink and opaque.
Drain the shrimp and immediately plunge them into an ice bath to stop the cooking process and keep them tender.
Once cooled, pat the shrimp dry and chop them into bite-sized pieces, then place them in a large glass mixing bowl.
Whisk together the lime juice, chili powder, sea salt, and black pepper in a small ramekin before pouring over the shrimp.
Add the diced cucumber, tomato, red onion, and minced jalapeño to the bowl and toss thoroughly to combine.
Cover and refrigerate for at least 15 minutes to allow the citrus and spices to fully marinate the ingredients.
Just before serving, gently fold in the diced avocado and fresh cilantro to ensure the avocado stays firm and the herbs remain vibrant.