Wash cucumbers thoroughly under cold water and slice them thinly, aiming for a thickness of about 1/8 inch.

Sprinkle salt evenly over cucumber slices in a colander and let sit for 10 minutes.

Blot cucumber slices with a paper towel to absorb any remaining moisture.

In a small bowl, combine rice vinegar and sugar, heat for 30 seconds in the microwave, and stir until dissolved.

In a large bowl, add cucumber slices, red onion, and cilantro, then pour the vinegar mixture over the salad and mix gently.

Cover the bowl and refrigerate for at least 20 minutes.

Sprinkle chopped peanuts on top right before serving, then toss gently to combine.

Transfer to a serving dish and enjoy.