Pat shrimp dry with paper towels. Season flour with salt and pepper in a shallow bowl.
In one bowl, place flour; in a second bowl, beaten eggs; in a third bowl, mix panko and shredded coconut.
Dredge each shrimp in flour, then dip into egg, then coat in the panko-coconut mixture. Press gently to adhere.
Heat 1–2 inches of vegetable oil in a skillet to 350°F (175°C).
Fry shrimp in batches for 2–3 minutes per side, until golden brown and crispy. Drain on a paper towel-lined plate.
In a small bowl, whisk together mayonnaise, sweet chili sauce, sriracha (if using), and lime juice.
Serve shrimp hot with sweet chili mayo for dipping.