Bring a small pot of water to a boil and blanch the shrimp for 90 seconds until just pink and opaque.
Immediately transfer the shrimp to an ice bath to stop the cooking, then drain and chop into half-inch pieces.
In a glass bowl, combine the chopped shrimp with the lime juice and lemon juice, ensuring the shrimp is fully submerged.
Cover the bowl and refrigerate for 20 minutes to allow the shrimp to finish 'cooking' in the acid and absorb the citrus flavor.
While the shrimp marinates, slice the corn tortilla into wedges and bake at 375°F for 8-10 minutes until golden and crunchy.
Remove the shrimp from the fridge and stir in the diced cucumber, tomato, red onion, jalapeño, and cilantro.
Season the mixture with sea salt and black pepper, then gently fold in the diced avocado to maintain its shape.
Serve the chilled ceviche immediately in a bowl with the warm, baked tortilla chips on the side.