Bring a large pot of salted water to a rolling boil. Add fresh corn kernels and cook for 5–7 minutes until tender yet crisp. Drain the corn and spread it out on a baking sheet to cool.

Dice the cucumber, slice the cherry tomatoes in half, and chop the red onion. In a large mixing bowl, combine the cooled corn, diced cucumber, halved cherry tomatoes, and chopped red onion.

In a separate bowl, whisk together the mayonnaise, sour cream, and lime juice until creamy. Add chili powder, salt, and pepper to taste.

Pour the dressing over the vegetable mixture and gently toss everything together until fully coated.

Crumble feta cheese over the top and sprinkle with chopped cilantro. Serve immediately or refrigerate for up to an hour to let the flavors meld.