Bring a large pot of heavily salted water to a boil. Meanwhile, finely grate the zest of 1 to 2 medium limes until you have 1 tablespoon zest and refrigerate for garnish. Juice the limes until you have 2 tablespoons and place the juice in a large bowl. Add 5 tablespoons olive oil, 3/4 teaspoon kosher salt, and 1/4 teaspoon black pepper; whisk until emulsified.

Add 1 pound pasta to the boiling water and cook according to package directions until al dente, 10 to 12 minutes. Meanwhile, dice 1 small red onion and place in a large fine-mesh strainer. Coarsely chop 1/2 cup fresh cilantro. Dice 2 avocados.

When the pasta is ready, drain over the onion. Rinse with cold water to cool. Drain well. Transfer the pasta and onions to the bowl with the dressing. Add the cilantro, avocado, and 2 cups fresh or frozen corn kernels and toss to combine. Taste and season with more salt and pepper as needed. Sprinkle with the reserved lime zest.