Bring a pot of water to a boil and poach the shrimp for 2 minutes until pink; drain and immediately plunge into an ice bath.
Chop the chilled shrimp into bite-sized pieces and place them in a glass bowl.
Add the lime juice and lemon juice to the shrimp, ensuring they are fully submerged, and refrigerate for 15 minutes.
While the shrimp marinates, cut the corn tortilla into triangles and bake at 375°F for 8-10 minutes until crisp.
Fold the diced cucumber, tomato, red onion, jalapeño, and cilantro into the shrimp mixture.
Season the ceviche with chili powder, sea salt, and black pepper.
Gently stir in the diced avocado just before serving to maintain its texture.
Serve the zesty ceviche in a chilled bowl with the warm tortilla chips on the side.