Prepare the cucumber bases: Slice the cucumbers into rounds approximately 1/2 inch thick. Pat the rounds dry thoroughly with paper towels to ensure they remain crisp.

Make the avocado spread: In a small bowl, mash the ripe avocado until relatively smooth. Stir in the lime juice, salt, black pepper, and chopped cilantro until well combined. Taste and adjust seasoning as needed.

Prepare the shrimp: If the shrimp are large, slice them in half horizontally so they are easier to place on the cucumber rounds. In a separate small bowl, toss the cooked shrimp with the smoked paprika and Old Bay seasoning.

Assemble the appetizers: Spread a generous teaspoon of the avocado mixture onto each cucumber slice, ensuring the base is covered.

Top each avocado-covered slice with one or two pieces of the seasoned shrimp. If desired, garnish with a tiny sprig of fresh dill or a pinch of chili flakes.

Serve immediately for the best texture, or chill assembled appetizers for up to 30 minutes before serving.