In a small bowl, combine mayonnaise, sweet chili sauce, and Sriracha.
For the Shrimp
In a large Dutch Oven, heat about 2 inches of oil to 375 degrees.
In a large bowl, combine shrimp and buttermilk. Place corn starch into a Ziploc baggie. Add shrimp to baggie being sure to shake off any extra buttermilk.
Shake until well coated.
Fry a few at a time for 1-2 minutes per side. Do not overcrowd the pan.
Drain on paper towels. Coat or drizzle with prepared sauce.