Combine mayonnaise, Sriracha sauce, salt, and lime juice in a small bowl. Cover and refrigerate.
In a large bowl, whisk together the egg, mayonnaise, mustard, Worcestershire sauce, smoked paprika, Old Bay, parsley, green onions, black pepper, and salt.
Place the crabmeat on top, followed by the crumbled saltine crackers. With a rubber spatula or large spoon, gently fold everything together. Break up crab meat slightly.
Form the crabmeat mixture into 4 patties about 1 1/2 inches thick and place on a wax paper-lined cooking sheet or baking pan. Cover tightly and refrigerate for at least 30 minutes.
In a large skillet over medium-high heat, heat oil until shimmering. Add the crab cakes and cook until golden brown, crispy, and heated through, approximately 3 minutes per side.
While the crab cakes cook, brush the cut sides of the slider buns with melted butter and toast in a dry skillet over medium heat until golden, about 1 to 2 minutes.
Spread a generous layer of spicy remoulade on the bottom bun. Top with a crab cake, then arugula, tomato, or microgreens, as desired. Add the top bun and serve immediately with lemon wedges.