In a large bowl or stand mixer, combine warm water, sugar, and yeast. Let sit 5 minutes until foamy. Add flour, salt, and melted butter. Mix until shaggy dough forms. Knead 5-7 minutes on floured surface until smooth and elastic. Cover and rest 10 minutes.
Preheat oven to 425°F (220°C). Line baking sheet with parchment paper. Bring 8 cups water to boil in a large pot and carefully stir in baking soda.
Divide dough into 6 pieces. Roll each into a 1-inch thick rope and cut into 1-inch bites. Working in batches, drop bites into boiling baking soda water 20-30 seconds. Remove with slotted spoon and place on prepared baking sheet.
Arrange bites in single layer, sprinkle with coarse sea salt. Bake 12-15 minutes until deep golden brown. Cool slightly before serving warm.
Notes
Brush baked pretzel bites with melted butter for extra flavor. Add baking soda to boiling water slowly, as it will fizz aggressively. Best served fresh; store in airtight container up to 2 days and reheat in oven to refresh.