Drain and rinse the soaked chickpeas. Add them to a food processor along with onion, parsley, cilantro, garlic, cumin, coriander, salt, black pepper, and cayenne pepper.
Pulse until the mixture is well combined and resembles coarse sand. Be careful not to over-process.
Transfer the mixture to a bowl and add the baking soda and flour. Combine everything evenly.
Shape the mixture into small balls or patties.
Heat vegetable oil in a deep pan over medium heat. Once hot, fry the falafel in batches until golden brown and crispy, about 2-3 minutes per side.
Remove falafel from oil and drain on paper towels.
Serve hot, with pita bread, tahini sauce, or as you prefer.